从网络获取图片与网页

1>网络----获取数据(图片、网页、xml、Json等)
A.从网络获取一张图片，然后显示在手机上；
B.从网络获取网页的html代码，然后显示在手机上；

从Internet获取数据利用HttpURLConnection对象,我们可以从网络中获取网页数据.URL url = new URL("http://www.sohu.com");HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setConnectTimeout(5* 1000);//设置连接超时conn.setRequestMethod(“GET”);//以get方式发起请求if (conn.getResponseCode() != 200) throw new RuntimeException("请求url失败");InputStream is = conn.getInputStream();//得到网络返回的输入流String result = readData(is, "GBK");conn.disconnect();//第一个参数为输入流,第二个参数为字符集编码public static String readData(InputStream inSream, String charsetName) throws Exception{ByteArrayOutputStream outStream = new ByteArrayOutputStream();byte[] buffer = new byte[1024];int len = -1;while( (len = inSream.read(buffer)) != -1 ){outStream.write(buffer, 0, len);}byte[] data = outStream.toByteArray();outStream.close();inSream.close();return new String(data, charsetName);}利用HttpURLConnection对象,我们可以从网络中获取文件数据.URL url = new URL("http://photocdn.sohu.com/20100125/Img269812337.jpg");HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setConnectTimeout(5* 1000);conn.setRequestMethod("GET");if (conn.getResponseCode() != 200) throw new RuntimeException("请求url失败");InputStream is = conn.getInputStream();readAsFile(is, "Img269812337.jpg"); public static void readAsFile(InputStream inSream, File file) throws Exception{FileOutputStream outStream = new FileOutputStream(file);byte[] buffer = new byte[1024];int len = -1;while( (len = inSream.read(buffer)) != -1 ){outStream.write(buffer, 0, len);} outStream.close();inSream.close();}

j2se测试网络代码；ImageRequest.javapackage cn.itcast.net;import java.io.ByteArrayOutputStream;import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;public class ImageRequest {public static void main(String[] args) throws Exception {//URL封装web访问路径；URL url = new URL("http://1801.img.pp.sohu.com.cn/images/2010/1/4/20/5/126a35eabd5mm.jpg");//打开连接；HttpURLConnection conn =  (HttpURLConnection) url.openConnection();conn.setRequestMethod("GET");conn.setConnectTimeout(5*1000);InputStream inStream = conn.getInputStream();//通过输入流获取图片数据；byte[] imageData = readInputStream(inStream);File imagefile = new File("beauty.jpg"); FileOutputStream fos = new FileOutputStream(imagefile);fos.write(imageData);  //把图片的二进制数据写入到文件中；fos.close();}/** * 从流里读取数据；以二进制形式返回； * @param inStream * @return * @throws Exception */public static byte[] readInputStream(InputStream inStream) throws Exception{ByteArrayOutputStream outStream = new ByteArrayOutputStream();byte[] buffer = new byte[1024];int len = 0;while((len = inStream.read(buffer)) != -1){//没有读到末尾一直循环；outStream.write(buffer, 0, len);//将buffer的数据写到内存中；}inStream.close();return outStream.toByteArray();}}

android 浏览网页图片：StreamTool.java--------工具类package cn.itcast.utils;import java.io.ByteArrayOutputStream;import java.io.InputStream;public class StreamTool {/** * 从流里读取数据；以二进制形式返回； * @param inStream * @return * @throws Exception */public static byte[] readInputStream(InputStream inStream) throws Exception{ByteArrayOutputStream outStream = new ByteArrayOutputStream();byte[] buffer = new byte[1024];int len = 0;while((len = inStream.read(buffer)) != -1){//没有读到末尾一直循环；outStream.write(buffer, 0, len);//将buffer的数据写到内存中；}inStream.close();return outStream.toByteArray();}}ImageService.java------服务类package cn.itcast.service;import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;import cn.itcast.utils.StreamTool;public class ImageService {/** * 返回图像的二进制数据； * @param path * @return * @throws Exception */public static byte[] getImage(String path) throws Exception {//URL封装web访问路径；URL url = new URL(path);//打开连接；HttpURLConnection conn =  (HttpURLConnection) url.openConnection();conn.setRequestMethod("GET");conn.setConnectTimeout(5*1000);InputStream inStream = conn.getInputStream();//通过输入流获取图片数据；return StreamTool.readInputStream(inStream);}}

资源文件strings.xml<?xml version="1.0" encoding="utf-8"?><resources>    <string name="app_name">图片浏览器</string>    <string name="urlpath">网络图片地址</string>    <string name="button">显示</string>    <string name="error">网络连接超时</string></resources>main.xml<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" >    <TextView      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="@string/urlpath"    />    <EditText      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="http://1801.img.pp.sohu.com.cn/images/2010/1/4/20/5/126a35eabd5mm.jpg"    android:id="@+id/urlpath"    />    <Button android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:text="@string/button"    android:id="@+id/button"    />    <ImageView android:layout_width="wrap_content"     android:layout_height="wrap_content"    android:id="@+id/imageView"    />    </LinearLayout>

ImageViewActivity.javapackage cn.itcast.image;import cn.itcast.service.ImageService;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.Bundle;import android.util.Log;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.ImageView;import android.widget.Toast;public class ImageViewActivity extends Activity {private static final String TAG = "ImageViewActivity";private EditText pathText;private ImageView imageView;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                pathText = (EditText) this.findViewById(R.id.urlpath);        imageView = (ImageView) this.findViewById(R.id.imageView);        Button button = (Button) this.findViewById(R.id.button);        button.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View arg0) {String path = pathText.getText().toString();try {byte[] data = ImageService.getImage(path);Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);//生成位图imageView.setImageBitmap(bitmap);//显示图片} catch (Exception e) {Toast.makeText(ImageViewActivity.this, R.string.error, 1).show();Log.e(TAG, e.toString());}}});            }}

在AndroidManifest.xml中添加网络访问权限<!-- 访问internet权限 --><uses-permission android:name="android.permission.INTERNET"/>

 显示html代码；

j2se测试代码HtmlRequest.javapackage cn.itcast.net;import java.io.ByteArrayOutputStream;import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;public class HtmlRequest {public static void main(String[] args) throws Exception {//URL封装web访问路径；URL url = new URL("http://www.sohu.com/");//打开连接；HttpURLConnection conn =  (HttpURLConnection) url.openConnection();conn.setRequestMethod("GET");conn.setConnectTimeout(5*1000);InputStream inStream = conn.getInputStream();//通过输入流获取html代码数据；byte[] data = readInputStream(inStream);//得到html的二进制数据String html = new String(data);System.out.println(html);}/** * 从流里读取数据；以二进制形式返回； * @param inStream * @return * @throws Exception */public static byte[] readInputStream(InputStream inStream) throws Exception{ByteArrayOutputStream outStream = new ByteArrayOutputStream();byte[] buffer = new byte[1024];int len = 0;while((len = inStream.read(buffer)) != -1){//没有读到末尾一直循环；outStream.write(buffer, 0, len);//将buffer的数据写到内存中；}inStream.close();return outStream.toByteArray();}}

StreamTool.javapackage cn.itcast.utils;import java.io.ByteArrayOutputStream;import java.io.InputStream;public class StreamTool {/** * 从流里读取数据；以二进制形式返回； * @param inStream * @return * @throws Exception */public static byte[] readInputStream(InputStream inStream) throws Exception{ByteArrayOutputStream outStream = new ByteArrayOutputStream();byte[] buffer = new byte[1024];int len = 0;while((len = inStream.read(buffer)) != -1){//没有读到末尾一直循环；outStream.write(buffer, 0, len);//将buffer的数据写到内存中；}inStream.close();return outStream.toByteArray();}}HtmlService.javapackage cn.itcast.service;import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;import cn.itcast.utils.StreamTool;public class HtmlService {/** * 返回html的二进制数据； * @param path * @return * @throws Exception */public static String getHtml(String path) throws Exception {//URL封装web访问路径；URL url = new URL(path);//打开连接；HttpURLConnection conn =  (HttpURLConnection) url.openConnection();conn.setRequestMethod("GET");conn.setConnectTimeout(5*1000);InputStream inStream = conn.getInputStream();//通过输入流获取html代码数据；byte[] data = StreamTool.readInputStream(inStream);//得到html的二进制数据String html = new String(data);return html;}}

 

main.xml<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" ><ScrollView     android:layout_width="fill_parent"     android:layout_height="fill_parent">    <TextView        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:id="@+id/textView"        /></ScrollView>    </LinearLayout>AndroidManifest.xml-----资源清单文件<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="cn.itcast.html"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk android:minSdkVersion="8" />    <application        android:icon="@drawable/ic_launcher"        android:label="@string/app_name" >        <activity            android:name=".MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application><!-- 访问网络的权限 --><uses-permission android:name="android.permission.INTERNET"/></manifest>

MainActivity.javapackage cn.itcast.html;import cn.itcast.service.HtmlService;import android.app.Activity;import android.os.Bundle;import android.util.Log;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends Activity {private TextView textView;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                textView = (TextView) this.findViewById(R.id.textView);        try {        textView.setText(HtmlService.getHtml("http://www.sohu.com"));} catch (Exception e) {Log.e("MainActivity", e.toString());Toast.makeText(MainActivity.this, "网络连接失败", 1).show();}    }}