android 内容保存

1.文件
2.sharepreference
3.content provider

1.文件
创建的文件位于/data/data/包名/files/文件名

package com.example.file;import java.io.ByteArrayOutputStream;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import android.content.Context;public class FileService {private Context context;public FileService(Context context) {super();this.context = context;}/** * 保存文件 * @param filename * @param filecontent * @throws FileNotFoundException  */public void save(String filename, String filecontent) throws FileNotFoundException {// TODO Auto-generated method stubFileOutputStream outStream = context.openFileOutput(filename, Context.MODE_PRIVATE);try {outStream.write(filecontent.getBytes());} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}try {outStream.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}public String read(String filename) throws IOException {FileInputStream inStream = context.openFileInput(filename);//将读出的内容先写入内存，全部读完之后，一块返回ByteArrayOutputStream outStream = new ByteArrayOutputStream();byte[] buffer = new byte[1024];int len =0;while((len = inStream.read(buffer)) != -1 ){outStream.write(buffer,0,len);}byte[] data = outStream.toByteArray();inStream.close();outStream.close();String s=new String(data);return s;}}

调用

String filename=mEditName.getText().toString();String filecontent=mEditContent.getText().toString();FileService service = new FileService(getApplicationContext());try {service.save(filename,filecontent);} catch (FileNotFoundException e) {// TODO Auto-generated catch blockToast.makeText(getApplicationContext(), "failed", Toast.LENGTH_SHORT);e.printStackTrace();}

String filename=mEditName.getText().toString();FileService service = new FileService(getApplicationContext());try {String content=service.read(filename);mEditContent.setText(content);} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}

2.sharepreference
业务类

package com.example.service;import java.util.HashMap;import java.util.Map;import android.content.Context;import android.content.SharedPreferences;import android.content.SharedPreferences.Editor;import android.preference.EditTextPreference;public class PreferService {private Context context;public PreferService( Context c) {// TODO Auto-generated method stubthis.context=c;}/** * 保存参数 * @param name * @param age */public void save(String name, Integer age) {// TODO Auto-generated method stubSharedPreferences sh =context.getSharedPreferences("shareprefer", Context.MODE_PRIVATE);//从上下文获取SharedPreferencesEditor editor = sh.edit();editor.putString("name", name);editor.putInt("age", age);editor.commit();}/** * 获取参数 * @return */public Map<String ,String> getPreference(){Map<String ,String> map =new  HashMap<String ,String>();SharedPreferences sh = context.getSharedPreferences("shareprefer", Context.MODE_PRIVATE);map.put("name", sh.getString("name", ""));map.put("age", String.valueOf(sh.getInt("age", 0)));return map;}}

在activity中调用

package com.example.a;import java.util.Map;import com.example.service.PreferService;import android.os.Bundle;import android.app.Activity;import android.util.Log;import android.view.Menu;import android.view.View;import android.view.Window;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class MainActivity extends Activity {private Button m_bt1;private EditText m_edt1;private EditText m_edt2;private PreferService service;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        m_bt1 = (Button)findViewById(R.id.button1);        m_edt1 =(EditText)findViewById(R.id.editText1);        m_edt2 =(EditText)findViewById(R.id.editText2);                        service =new PreferService(this);//传递一个上下文参数        //service =new PreferService(getApplicationContext());        Map<String , String> map = service.getPreference();                m_edt1.setText(map.get("name"));        m_edt2.setText(map.get("age"));                m_bt1.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {service.save(m_edt1.getText().toString(),Integer.parseInt(m_edt2.getText().toString()));Toast.makeText(getApplicationContext(), R.string.success, Toast.LENGTH_SHORT).show();}});    }    }