安卓小案例收集二

收集二

SQLite数据库

OpenHelper类：

public class MyOpenHelper extends SQLiteOpenHelper {    public MyOpenHelper(Context context) {        //本来是四个参数，改成1个，其他写死了        //arg1:数据库文件名字        //arg2：游标工厂，游标等同于结果集，传null使用默认工厂        //arg3：版本，不能小于1，用于升级        super(context, "people.db", null, 1);    }    //创建数据库时调用    @Override    public void onCreate(SQLiteDatabase db) {        //创建表        db.execSQL("create table person(_id integer primary key autoincrement, name char(10), phone char(20), salary integer(10))");    }    //升级数据库时调用    @Override    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {        System.out.println("数据库升级");    }}

Test类中的调用

public class Test extends AndroidTestCase{    private MyOpenHelper oh;    private SQLiteDatabase db;    public void test(){        //获取虚拟上下文        MyOpenHelper oh = new MyOpenHelper(getContext());        //如果数据库不存在，先创建，再打开，如果存在，就直接打开        SQLiteDatabase db = oh.getWritableDatabase();    }    //测试方法执行前调用    @Override    protected void setUp() throws Exception {        super.setUp();        oh = new MyOpenHelper(getContext());        db = oh.getWritableDatabase();    }    @Override    protected void tearDown() throws Exception {        super.tearDown();        db.close();    }    public void insert(){//      db.execSQL("insert into person(name, phone, salary) values (?, ?, ?)", new Object[]{"一", "138438", 13000});        db.execSQL("insert into person(name, phone, salary) values (?, ?, ?)", new Object[]{"二 ", "138438", 13000});        db.execSQL("insert into person(name, phone, salary) values (?, ?, ?)", new Object[]{"三", "138438", 13000});    }    public void delete(){        db.execSQL("delete from person where name = ?", new Object[]{"一"});    }    public void update(){        db.execSQL("update person set salary = ? where name = ?", new Object[]{13200, "一"});    }    public void select(){        Cursor cursor = db.rawQuery("select * from person", null);        //把指针移动至下一行        while(cursor.moveToNext()){            //先通过列名，获取列索引，然后再获取该列的内容            String name = cursor.getString(cursor.getColumnIndex("name"));            String phone = cursor.getString(cursor.getColumnIndex("phone"));            int salary = cursor.getInt(cursor.getColumnIndex("salary"));            System.out.println(name + ";" + phone + ";" + salary);        }    }    public void insertApi(){        ContentValues values = new ContentValues();        values.put("name", "杨松");        values.put("phone", "1388888");        values.put("salary", "13201");        //返回值-1，插入失败        long l = db.insert("person", null, values);        System.out.println(l);    }    public void deleteApi(){        int i = db.delete("person", "_id = ?", new String[]{"6"});        System.out.println(i);    }    public void updateApi(){        ContentValues values = new ContentValues();        values.put("name", "二二");        int i = db.update("person", values, "_id = ?", new String[]{"5"});        System.out.println(i);    }    public void selectApi(){        //arg1: 查询的字段        //arg2: 查询的where条件        //arg3: where条件的占位符        Cursor cursor = db.query("person", null, null, null, null, null, null, null);        while(cursor.moveToNext()){            String name = cursor.getString(1);            String phone = cursor.getString(2);            int salary = cursor.getInt(3);            System.out.println(name + ";" + phone + ";" + salary);        }    }    public void transaction(){        try{            //开启事务            db.beginTransaction();            ContentValues values = new ContentValues();            values.put("salary", 13199);            db.update("person", values, "name = ?", new String[]{"二二"});            //清空values的内容            values.clear();            values.put("salary", 13202);            db.update("person", values, "name = ?", new String[]{"一"});//          int i = 9 / 0;            //设置事务执行成功，提交时如果这行代码没有执行过，就会回滚            db.setTransactionSuccessful();        }        catch (Exception e) {            e.printStackTrace();        }        finally{            //关闭事务，提交数据            db.endTransaction();        }    }}

ListView使用

protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        personList = new ArrayList<Person>();        //查询数据库        MyOpenHelper oh = new MyOpenHelper(this);        SQLiteDatabase db = oh.getWritableDatabase();        Cursor cursor = db.query("person", null, null, null, null, null, null, null);        while(cursor.moveToNext()){            String name = cursor.getString(1);            String phone = cursor.getString(2);            int salary = cursor.getInt(3);            Person p = new Person(name, phone, salary);            personList.add(p);        }        //找到listview        ListView lv = (ListView) findViewById(R.id.lv);        //设置显示内容        lv.setAdapter(new MyAdapter());    }    class MyAdapter extends BaseAdapter{        //系统调用，用来获知模型层有多少条数据        @Override        public int getCount() {            return personList.size();        }        //系统调用，返回的View对象就会作为ListView的一个条目显示在屏幕上        //position:该次getView调用返回的View对象在ListView中是第几个条目,position的值就是几        //convertView:系统之前缓存的条目        @Override        public View getView(int position, View convertView, ViewGroup parent) {            System.out.println("getView方法调用" + position + ":" + convertView);            Person p = personList.get(position);            //          TextView tv = new TextView(MainActivity.this);//          tv.setText(p.toString());//          tv.setTextSize(16);                 //获取布局填充器//          LayoutInflater inflater = LayoutInflater.from(MainActivity.this);//          LayoutInflater inflater = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);//          View view = inflater.inflate(R.layout.item_listview, null);                     View view = null;            if(convertView == null){                //把布局文件填充成view对象                view = View.inflate(MainActivity.this, R.layout.item_listview, null);            }            else{                view = convertView;            }            //必须使用view.findViewById            TextView tv_name = (TextView) view.findViewById(R.id.tv_name);            tv_name.setText(p.getName());            TextView tv_phone = (TextView) view.findViewById(R.id.tv_phone);            tv_phone.setText(p.getPhone());            TextView tv_salary = (TextView) view.findViewById(R.id.tv_salary);            tv_salary.setText(p.getSalary() + "");//不能用整形会被做为id使用            return view;        }        @Override        public Object getItem(int position) {            return null;        }        @Override        public long getItemId(int position) {            return 0;        }    }

ArrayAdapter和SimpleAdapter的使用

protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        String[] objects = new String[]{                "一",                "二",                "三"        };              ListView lv = (ListView) findViewById(R.id.lv);//      lv.setAdapter(new ArrayAdapter<String>(this, R.layout.item_listview, //指定作为条目的布局文件//              R.id.tv, //指定文本显示在哪个文本框//              objects));        //把每个条目需要处理的所有数据封装至map中,在把map封装至list中        //这样就保证了list每个元素都包含了一个条目需要的所有数据        List<Map<String, Object>> data = new ArrayList<Map<String,Object>>();        Map<String, Object> map1 = new HashMap<String, Object>();        map1.put("name", "周杰伦");        map1.put("photo", R.drawable.photo1);        data.add(map1);        Map<String, Object> map2 = new HashMap<String, Object>();        map2.put("name", "刘德华");        map2.put("photo", R.drawable.photo2);        data.add(map2);        Map<String, Object> map3 = new HashMap<String, Object>();        map3.put("name", "侃哥");        map3.put("photo", R.drawable.photo3);        data.add(map3);        lv.setAdapter(new SimpleAdapter(this, data, R.layout.item_listview,                 new String[]{"name", "photo"}, //存放键的数组                new int[]{R.id.tv, R.id.iv}));//存放资源id的数组，两个数组用下标来对应    }

网络请求下载图片

public void click(View v){    String path = "http://169.254.244.136:8080/dd.jpg";    //发送http请求    try {        //1.使用网址构造一个URL对象        URL url = new URL(path);        //2.获取连接对象        HttpURLConnection conn = (HttpURLConnection) url.openConnection();        //3.设置一些属性        //设置请求方式，注意大写        conn.setRequestMethod("GET");        //设置请求超时        conn.setConnectTimeout(8000);        //设置读取超时        conn.setReadTimeout(8000);        //4.发送请求，建立连接        conn.connect();        //5.判断请求是否成功        if(conn.getResponseCode() == 200){            //获取服务器返回的流，流里就是客户端请求的数据            InputStream is = conn.getInputStream();            //读取流里的数据，构造出一张图片            Bitmap bm = BitmapFactory.decodeStream(is);            //把下载的图片显示至imageview            ImageView iv = (ImageView) findViewById(R.id.iv);            iv.setImageBitmap(bm);        }        else{            Toast.makeText(this, "请求失败鸟o(╯□╰)o", 0).show();        }    } catch (Exception e) {        e.printStackTrace();    }}

子线程刷新页面，Handler的使用（网络请求必须在子线程）

Handler handler = new Handler(){    //只要消息队列有消息，此方法就会在主线程执行    public void handleMessage(android.os.Message msg) {        //在这里刷新ui        switch (msg.what) {        case 1:            ImageView iv = (ImageView) findViewById(R.id.iv);            iv.setImageBitmap((Bitmap)msg.obj);            break;        case 2:            Toast.makeText(MainActivity.this, "请求失败o(╯□╰)o", 0).show();            break;        }    }};public void click(View v){    Thread t = new Thread(){        @Override        public void run() {            String path = "http://169.254.244.136:8080/dd.jpg";            //发送http请求            try {                //1.使用网址构造一个URL对象                URL url = new URL(path);                //2.获取连接对象                HttpURLConnection conn = (HttpURLConnection) url.openConnection();                //3.设置一些属性                //设置请求方式，注意大写                conn.setRequestMethod("GET");                //设置请求超时                conn.setConnectTimeout(8000);                //设置读取超时                conn.setReadTimeout(8000);                //4.发送请求，建立连接                conn.connect();                //5.判断请求是否成功                if(conn.getResponseCode() == 200){                    //获取服务器返回的流，流里就是客户端请求的数据                    InputStream is = conn.getInputStream();                                 //读取流里的数据，构造出一张图片                    Bitmap bm = BitmapFactory.decodeStream(is);                                 //当子线程需要刷新ui时，只需发送一条消息至消息队列                    Message msg = new Message();                    //消息对象本身是可以携带数据的                    msg.obj = bm;                    //使用what标注消息是什么类型的                    msg.what = 1;                    handler.sendMessage(msg);                }                else{                    //如果消息池有消息，取出消息池第一条消息，返回，如果没有，就new一个消息返回//                      Message msg = handler.obtainMessage();//                      msg.what = 2;//                      handler.sendMessage(msg);                    handler.sendEmptyMessage(2);                }            } catch (Exception e) {                e.printStackTrace();            }        }    };    t.start();}

带缓存的图片下载

Handler handler = new Handler(){    //只要消息队列有消息，此方法就会在主线程执行    public void handleMessage(android.os.Message msg) {        //在这里刷新ui        switch (msg.what) {        case 1:            ImageView iv = (ImageView) findViewById(R.id.iv);            iv.setImageBitmap((Bitmap)msg.obj);            break;        case 2:            Toast.makeText(MainActivity.this, "请求失败o(╯□╰)o", 0).show();            break;        }    }};@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);}public void click(View v){    final String path = "http://169.254.244.136:8080/dd.jpg";    final File file = new File(getCacheDir(), getNameFromPath(path));    if(file.exists()){        System.out.println("从缓存获取");        Bitmap bm = BitmapFactory.decodeFile(file.getAbsolutePath());        Message msg = new Message();        msg.obj = bm;        msg.what = 1;        handler.sendMessage(msg);//          ImageView iv = (ImageView) findViewById(R.id.iv);//          iv.setImageBitmap((Bitmap)msg.obj);    }    else{        Thread t = new Thread(){            @Override            public void run() {                System.out.println("从网络获取");                //发送http请求                try {                    //1.使用网址构造一个URL对象                    URL url = new URL(path);                    //2.获取连接对象                    HttpURLConnection conn = (HttpURLConnection) url.openConnection();                    //3.设置一些属性                    //设置请求方式，注意大写                    conn.setRequestMethod("GET");                    //设置请求超时                    conn.setConnectTimeout(8000);                    //设置读取超时                    conn.setReadTimeout(8000);                    //4.发送请求，建立连接//                      conn.connect();                    //5.判断请求是否成功                    if(conn.getResponseCode() == 200){                        //获取服务器返回的流，流里就是客户端请求的数据                        InputStream is = conn.getInputStream();                        //我们自己读取流里的数据，读取1k，就把1k写到本地文件缓存起来                        byte[] b = new byte[1024];                        int len;                        FileOutputStream fos = new FileOutputStream(file);                        while((len = is.read(b)) != -1){                            fos.write(b, 0, len);                        }                        fos.close();//                      因为缓存时已经把流里数据读取完了，此时流里没有任何数据//                      Bitmap bm = BitmapFactory.decodeStream(is);                        Bitmap bm = BitmapFactory.decodeFile(file.getAbsolutePath());                        //当子线程需要刷新ui时，只需发送一条消息至消息队列                        Message msg = new Message();                        //消息对象本身是可以携带数据的                        msg.obj = bm;                        //使用what标注消息是什么类型的                        msg.what = 1;                        handler.sendMessage(msg);                    }                    else{                        //如果消息池有消息，取出消息池第一条消息，返回，如果没有，就new一个消息返回//                      Message msg = handler.obtainMessage();//                      msg.what = 2;//                      handler.sendMessage(msg);                        handler.sendEmptyMessage(2);                    }                } catch (Exception e) {                    e.printStackTrace();                }            }        };        t.start();    }}public String getNameFromPath(String path){    int index = path.lastIndexOf("/");    return path.substring(index + 1);}

使用SmartImageView 工具包（loopj）

public void click(View v){    SmartImageView siv = (SmartImageView) findViewById(R.id.siv);    //请求网络图片    siv.setImageUrl("http://169.254.244.136:8080/dd.jpg");}

请求html页面并显示其代码

读流的工具类

public class Tools {    public static String getTextFromStream(InputStream is){        byte[] b = new byte[1024];        int len;        ByteArrayOutputStream bos = new ByteArrayOutputStream();        try {            while((len = is.read(b)) != -1){                bos.write(b, 0, len);            }            //把字节数组输出流转换成字节数组，然后用字节数组构造一个字符串            String text = new String(bos.toByteArray());            return text;        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        return null;    }}

Handler handler = new Handler(){        public void handleMessage(android.os.Message msg) {            TextView tv = (TextView) findViewById(R.id.tv);            tv.setText((String)msg.obj);        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }    public void click(View v){        final String path = "http://169.254.244.136:8080/baidu.html";        Thread t = new Thread(){            @Override            public void run() {                //使用网址构造url                URL url;                try {                    url = new URL(path);                    //获取连接对象，做设置                    HttpURLConnection conn = (HttpURLConnection) url.openConnection();                    conn.setRequestMethod("GET");                    conn.setConnectTimeout(8000);                    conn.setReadTimeout(8000);                    //发送请求，获取响应码                    if(conn.getResponseCode() == 200){                        //获取服务器返回的输入流                        InputStream is = conn.getInputStream();                        String text = Tools.getTextFromStream(is);                        //发送消息至消息队列，主线程会执行handleMessage                        Message msg = handler.obtainMessage();                        msg.obj = text;                        handler.sendMessage(msg);                    }                } catch (Exception e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }            }        };        t.start();    }

模拟一个新闻客户端

News是新闻对象，实际以xml的方式存在服务器

List<News> newsList;    Handler handler = new Handler(){        public void handleMessage(android.os.Message msg) {            ListView lv = (ListView) findViewById(R.id.lv);            lv.setAdapter(new MyAdapter());        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        getNewsInfo();//      ListView lv = (ListView) findViewById(R.id.lv);        //此时新闻信息还没有解析完毕，newsList还没有new出来//      lv.setAdapter(new MyAdapter());    }    class MyAdapter extends BaseAdapter{        //返回的要显示的条目的数量        @Override        public int getCount() {            // TODO Auto-generated method stub            return newsList.size();        }        //返回一个View对象，会作为ListView的一个条目显示在界面上        @Override        public View getView(int position, View convertView, ViewGroup parent) {            News news = newsList.get(position);            View v = null;            ViewHolder mHolder = null;            if(convertView == null){                //如何填充的                v = View.inflate(MainActivity.this, R.layout.item_listview, null);                //创建viewHoler封装所有条目使用的组件                mHolder = new ViewHolder();                mHolder.tv_title = (TextView) v.findViewById(R.id.tv_title);                mHolder.tv_detail = (TextView) v.findViewById(R.id.tv_detail);                mHolder.tv_comment = (TextView) v.findViewById(R.id.tv_comment);                mHolder.siv = (SmartImageView) v.findViewById(R.id.siv);                //把viewHolder封装至view对象中，这样view被缓存时，viewHolder也就被缓存了                v.setTag(mHolder);            }            else{                v = convertView;                //从view中取出保存的viewHolder，viewHolder中就有所有的组件对象，不需要再去findViewById                mHolder = (ViewHolder) v.getTag();            }            //给条目中的每个组件设置要显示的内容            mHolder.tv_title.setText(news.getTitle());            mHolder.tv_detail.setText(news.getDetail());            mHolder.tv_comment.setText(news.getComment() + "条评论");            mHolder.siv.setImageUrl(news.getImageUrl());            return v;        }        //把条目需要使用到的所有组件封装在这个类中        class ViewHolder{            TextView tv_title;            TextView tv_detail;            TextView tv_comment;            SmartImageView siv;        }        @Override        public Object getItem(int position) {            return newsList.get(position);        }        @Override        public long getItemId(int position) {            return position;        }    }    private void getNewsInfo() {        Thread t = new Thread(){            @Override            public void run() {                String path = "http://169.254.244.136:8080/news.xml";                try {                    URL url = new URL(path);                    HttpURLConnection conn = (HttpURLConnection) url.openConnection();                    conn.setRequestMethod("GET");                    conn.setConnectTimeout(8000);                    conn.setReadTimeout(8000);                    if(conn.getResponseCode() == 200){                        //流里的信息是一个xml文件的文本信息，用xml解析器去解析，而不要作为文本去解析                        InputStream is = conn.getInputStream();                        getNewsFromStream(is);                    }                } catch (Exception e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }            }        };        t.start();    }    private void getNewsFromStream(InputStream is) {        //从XML对象中获取XML文件解析器对象。        XmlPullParser xp = Xml.newPullParser();        try {            xp.setInput(is, "utf-8");            //获取事件类型，通过事件类型判断出当前解析的是和什么节点            int type = xp.getEventType();            News news = null;            while(type != XmlPullParser.END_DOCUMENT){                switch (type) {                case XmlPullParser.START_TAG:                    if("newslist".equals(xp.getName())){                        newsList = new ArrayList<News>();                    }                    else if("news".equals(xp.getName())){                        news = new News();                    }                    else if("title".equals(xp.getName())){                        String title = xp.nextText();                        news.setTitle(title);                    }                    else if("detail".equals(xp.getName())){                        String detail = xp.nextText();                        news.setDetail(detail);                    }                    else if("comment".equals(xp.getName())){                        String comment = xp.nextText();                        news.setComment(comment);                    }                    else if("image".equals(xp.getName())){                        String image = xp.nextText();                        news.setImageUrl(image);                    }                    break;                case XmlPullParser.END_TAG:                    if("news".equals(xp.getName())){                        newsList.add(news);                    }                    break;                }                //指针移动到下一个节点并返回事件类型                type = xp.next();            }                   //发送消息，让主线程刷新listview            handler.sendEmptyMessage(1);//          for (News n : newsList) {//              System.out.println(n.toString());//          }        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }

get方式提交表单

Handler handler = new Handler(){    public void handleMessage(android.os.Message msg) {        Toast.makeText(MainActivity.this, (String)msg.obj, 0).show();    }};@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);}public void click(View v){    EditText et_name = (EditText) findViewById(R.id.et_name);    EditText et_pass = (EditText) findViewById(R.id.et_pass);    final String name = et_name.getText().toString();    final String pass = et_pass.getText().toString();    Thread t = new Thread(){        @Override        public void run() {            @SuppressWarnings("deprecation")            String path = "http://169.254.244.136/Web2/servlet/Login?name=" + URLEncoder.encode(name) + //对要提交的表单数据进行url编码                                                                                    "&pass=" + pass;            try {                URL url = new URL(path);                HttpURLConnection conn = (HttpURLConnection) url.openConnection();                conn.setRequestMethod("GET");                conn.setConnectTimeout(8000);                conn.setReadTimeout(8000);                if(conn.getResponseCode() == 200){                    InputStream is = conn.getInputStream();                    String text = Tools.getTextFromStream(is);                    Message msg = handler.obtainMessage();                    msg.obj = text;                    handler.sendMessage(msg);                }            } catch (Exception e) {                // TODO Auto-generated catch block                e.printStackTrace();            }        }    };    t.start();}

post方式提交

Handler handler = new Handler(){    public void handleMessage(android.os.Message msg) {        Toast.makeText(MainActivity.this, (String)msg.obj, 0).show();    }};@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);}public void click(View v){    EditText et_name = (EditText) findViewById(R.id.et_name);    EditText et_pass = (EditText) findViewById(R.id.et_pass);    final String name = et_name.getText().toString();    final String pass = et_pass.getText().toString();    Thread t = new Thread(){        @Override        public void run() {            String path = "http://169.254.244.136/Web2/servlet/Login";            try {                URL url = new URL(path);                HttpURLConnection conn = (HttpURLConnection) url.openConnection();                conn.setRequestMethod("POST");                conn.setConnectTimeout(8000);                conn.setReadTimeout(8000);                //添加post请求头中自动添加的属性                //流里的数据的mimetype                conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");                String content = "name=" + URLEncoder.encode(name) + "&pass=" + pass;                //流里数据的长度                conn.setRequestProperty("Content-Length", content.length() + "");                //打开连接对象的输出流                conn.setDoOutput(true);                //获取连接对象的输出流                OutputStream os = conn.getOutputStream();                //把数据写入输出流中                os.write(content.getBytes());                   if(conn.getResponseCode() == 200){                    InputStream is = conn.getInputStream();                    String text = Tools.getTextFromStream(is);                    Message msg = handler.obtainMessage();                    msg.obj = text;                    handler.sendMessage(msg);                }            } catch (Exception e) {                // TODO Auto-generated catch block                e.printStackTrace();            }        }    };    t.start();}

使用HttpClient提交表单

Handler handler = new Handler(){    public void handleMessage(android.os.Message msg) {        Toast.makeText(MainActivity.this, (String)msg.obj, 0).show();    }};   @Override   protected void onCreate(Bundle savedInstanceState) {       super.onCreate(savedInstanceState);       setContentView(R.layout.activity_main);   }   public void click1(View v){    //获取用户输入的账号密码    EditText et_name = (EditText) findViewById(R.id.et_name);    EditText et_pass = (EditText) findViewById(R.id.et_pass);    String name = et_name.getText().toString();    String pass = et_pass.getText().toString();    final String path = "http://169.254.244.136/Web2/servlet/Login?name=" + URLEncoder.encode(name) + "&pass=" + pass;    Thread t = new Thread(){        @Override        public void run() {            //使用httpClient框架提交            //1.创建client对象            HttpClient client = new DefaultHttpClient();            //2.创建get请求对象            HttpGet get = new HttpGet(path);            try {                //3.使用client发送get请求                HttpResponse response = client.execute(get);                //获取状态行                StatusLine line = response.getStatusLine();                //获取状态码                int code = line.getStatusCode();                if(code == 200){                    //获取实体                    HttpEntity entity = response.getEntity();                    InputStream is = entity.getContent();                    String text = Tools.getTextFromStream(is);                    Message msg = handler.obtainMessage();                    msg.obj = text;                    handler.sendMessage(msg);                }            } catch (Exception e) {                // TODO Auto-generated catch block                e.printStackTrace();            }        }    };    t.start();   }   public void click2(View v){    //获取用户输入的账号密码    EditText et_name = (EditText) findViewById(R.id.et_name);    EditText et_pass = (EditText) findViewById(R.id.et_pass);    final String name = et_name.getText().toString();    final String pass = et_pass.getText().toString();    final String path = "http://169.254.244.136/Web2/servlet/Login";    Thread t = new Thread(){        @Override        public void run() {            HttpClient client = new DefaultHttpClient();            HttpPost post = new HttpPost(path);            //把要提交的数据封装至post中            List<NameValuePair> parameters = new ArrayList<NameValuePair>();            //arg0:表单的名字            //arg1:表单中的值            BasicNameValuePair bnvp1 = new BasicNameValuePair("name", name);            BasicNameValuePair bnvp2 = new BasicNameValuePair("pass", pass);            //把BasicNameValuePair对象放入集合            parameters.add(bnvp1);            parameters.add(bnvp2);            //创建实体对象            UrlEncodedFormEntity entity = null;            try {                //把集合对象封装到实体中                entity = new UrlEncodedFormEntity(parameters, "utf-8");            } catch (Exception e1) {                e1.printStackTrace();            }            //把实体对象封装至post对象中            post.setEntity(entity);            try {                HttpResponse response = client.execute(post);                if(response.getStatusLine().getStatusCode() == 200){                    InputStream is = response.getEntity().getContent();                    String text = Tools.getTextFromStream(is);                    Message msg = handler.obtainMessage();                    msg.obj = text;                    handler.sendMessage(msg);                }            } catch (Exception e) {                e.printStackTrace();            }         }    };    t.start();   }

异步HttpClient

Handler handler = new Handler(){    public void handleMessage(android.os.Message msg) {        Toast.makeText(MainActivity.this, (String)msg.obj, 0).show();    }};   @Override   protected void onCreate(Bundle savedInstanceState) {       super.onCreate(savedInstanceState);       setContentView(R.layout.activity_main);   }   public void click1(View v){    //获取用户输入的账号密码    EditText et_name = (EditText) findViewById(R.id.et_name);    EditText et_pass = (EditText) findViewById(R.id.et_pass);    String name = et_name.getText().toString();    String pass = et_pass.getText().toString();    String path = "http://169.254.244.136/Web2/servlet/Login";    //使用异步HttpClient发送get请求    AsyncHttpClient client = new AsyncHttpClient();    //把要提交的数据封装在rp对象中    RequestParams rp = new RequestParams();    rp.put("name", name);    rp.put("pass", pass);    //发送get请求    client.get(path, rp, new MyHandler());   }   class MyHandler extends AsyncHttpResponseHandler{    //请求成功时回调    @Override    public void onSuccess(int statusCode, Header[] headers,            byte[] responseBody) {        Toast.makeText(MainActivity.this, new String(responseBody), 0).show();    }    //请求失败时回调    @Override    public void onFailure(int statusCode, Header[] headers,            byte[] responseBody, Throwable error) {        Toast.makeText(MainActivity.this, "请求失败", 0).show();    }   }   public void click2(View v){    //获取用户输入的账号密码    EditText et_name = (EditText) findViewById(R.id.et_name);    EditText et_pass = (EditText) findViewById(R.id.et_pass);    String name = et_name.getText().toString();    String pass = et_pass.getText().toString();    String path = "http://169.254.244.136/Web2/servlet/Login";    //使用异步HttpClient发送post请求    AsyncHttpClient client = new AsyncHttpClient();    //把要提交的数据封装在rp对象中    RequestParams rp = new RequestParams();    rp.put("name", name);    rp.put("pass", pass);    //发送get请求    client.post(path, rp, new MyHandler());   }