这程序怎么无法保存数据

 package com.example.tianjia;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.StringTokenizer;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class TianjiaActivity extends Activity implements OnClickListener {
        private EditText name,phone;
        private Button button;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_tianjia);
        name=(EditText)findViewById(R.id.name);
        phone=(EditText)findViewById(R.id.one);
        button=(Button)findViewById(R.id.bt1);
        button.setOnClickListener(this);
    }

     @Override
        public void onClick(View v) {
            switch (v.getId()) {
            case R.id.bt1:
        Intent intent=new Intent();
        Bundle bundle=new Bundle();
        String name1=name.getText().toString();
        String phone1=phone.getText().toString();
        FileInputStream in;
        BufferedReader read = null;
        String s1="",s2="";
        try {
                       in = openFileInput("date5");
                       read = new BufferedReader(new InputStreamReader(in));
                       String line = "";
                       while ((line = read.readLine()) != null) {
                           StringTokenizer st = new StringTokenizer(line, ";"); //设置数据之间 的分隔符为；
                            s1 = st.nextToken();//读取的时候是 String 类
                            s2 = st.nextToken();
                           if (s1.equals(name1) || s2.equals(phone1) ) {
                               Toast.makeText(TianjiaActivity.this, "该快捷拨号已存在", Toast.LENGTH_SHORT).show();
                               //AlertDialog alertDialog=new AlertDialog();
                               break;
                           }
                       }
                   }catch (IOException e){
                       e.printStackTrace();
                   }finally {
                       try {
                           if (read != null) {
                               read.close();
                           }
                       }catch(IOException e){
                           e.printStackTrace();
                       }
                   }
                    if(!s1.equals(name1)&&!s2.equals(phone1)&&!TextUtils.isEmpty(name1)&&!TextUtils.isEmpty(phone1))
                    {
                        Toast.makeText(TianjiaActivity.this, "关掉apk", Toast.LENGTH_LONG).show();
                        bundle.putString("name1",name1);
                        bundle.putString("phone1",phone1);
                        intent.putExtras(bundle);
                        setResult(RESULT_OK,intent);
                        finish();
                    }
            }
     }

    @Override
    protected void onDestroy() {
        Toast.makeText(TianjiaActivity.this, "正在保存数据", Toast.LENGTH_LONG).show();
        if(name.equals("")) {
            String Input1 = name.getText().toString();
            String Input2 = phone.getText().toString();
            if(!TextUtils.isEmpty(Input1)&&!TextUtils.isEmpty(Input2)) 
                save(Input1, Input2);
        }
        super.onDestroy();
    }
    public void save(String i1,String i2){
        FileOutputStream out;
        BufferedWriter writer=null;
        FileInputStream in;
        BufferedReader read=null;
        String s1=null,s2=null;
        try{
            out=openFileOutput("date5", Context.MODE_APPEND);
            in=openFileInput("date5");
            writer=new BufferedWriter(new OutputStreamWriter(out));
            read = new BufferedReader(new InputStreamReader(in));
            String line="";
            while((line=read.readLine())!=null){
                StringTokenizer st = new StringTokenizer(line, ";"); //设置数据之间 的分隔符为；
                 s1 = st.nextToken();//读取的时候是 String 类
                 s2 = st.nextToken();
                if(s1.equals(i1)||s2.equals(i2)) {
                    Toast.makeText(TianjiaActivity.this, "该快捷拨号已存在", Toast.LENGTH_SHORT).show();
                    return;
                }
            }
            if(!s1.equals(i1)&&!s2.equals(i2)&&!TextUtils.isEmpty(i1)&&!TextUtils.isEmpty(i2)) {
                writer.write(i1);
                writer.write(";");
                writer.write(i2);
                writer.write(";");
                writer.newLine();
            }
        }catch(IOException e){
            e.printStackTrace();
        }finally {
            try {
                if (writer != null) {
                    writer.close();
                }
            }catch(IOException e){
                    e.printStackTrace();
                }
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.tianjia, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

当你开了文件流写入数据后,在DDMS里看下相应目录文件夹下有没有写入成功,不过不推荐用XML文件保存,SharePerfrence这么好的持久化API你为啥不用呢...

qwddefwefwefwefw

为什么不试试神奇的sharepreference呢

首先你得看看你文件是不是创建成功了

找到问题了，是if(name.equals(""))这个报了空指针错误

 package com.example.tianjia;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.StringTokenizer;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class TianjiaActivity extends Activity implements OnClickListener {
        private EditText name,phone;
        private Button button;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_tianjia);
        name=(EditText)findViewById(R.id.name);
        phone=(EditText)findViewById(R.id.one);
        button=(Button)findViewById(R.id.bt1);
        button.setOnClickListener(this);
    }

     @Override
        public void onClick(View v) {
            switch (v.getId()) {
            case R.id.bt1:
        Intent intent=new Intent();
        Bundle bundle=new Bundle();
        String name1=name.getText().toString();
        String phone1=phone.getText().toString();
        FileInputStream in;
        BufferedReader read = null;
        String s1="",s2="";
        try {
                       in = openFileInput("date5");
                       read = new BufferedReader(new InputStreamReader(in));
                       String line = "";
                       while ((line = read.readLine()) != null) {
                           StringTokenizer st = new StringTokenizer(line, ";"); //设置数据之间 的分隔符为；
                            s1 = st.nextToken();//读取的时候是 String 类
                            s2 = st.nextToken();
                           if (s1.equals(name1) || s2.equals(phone1) ) {
                               Toast.makeText(TianjiaActivity.this, "该快捷拨号已存在", Toast.LENGTH_SHORT).show();
                               //AlertDialog alertDialog=new AlertDialog();
                               break;
                           }
                       }
                   }catch (IOException e){
                       e.printStackTrace();
                   }finally {
                       try {
                           if (read != null) {
                               read.close();
                           }
                       }catch(IOException e){
                           e.printStackTrace();
                       }
                   }
                    if(!s1.equals(name1)&&!s2.equals(phone1)&&!TextUtils.isEmpty(name1)&&!TextUtils.isEmpty(phone1))
                    {
                        Toast.makeText(TianjiaActivity.this, "关掉apk", Toast.LENGTH_LONG).show();
                        bundle.putString("name1",name1);
                        bundle.putString("phone1",phone1);
                        intent.putExtras(bundle);
                        setResult(RESULT_OK,intent);
                        finish();
                    }
            }
     }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        Toast.makeText(TianjiaActivity.this, "正在保存数据", Toast.LENGTH_LONG).show();
            String Input1 = name.getText().toString();
            String Input2 = phone.getText().toString();
            if(!TextUtils.isEmpty(Input1)&&!TextUtils.isEmpty(Input2)) 
                save(Input1, Input2);
    }
    public void save(String i1,String i2){
        FileOutputStream out;
        BufferedWriter writer=null;
        FileInputStream in;
        BufferedReader read=null;
        String s1=null,s2=null;
        try{
            out=openFileOutput("date5", Context.MODE_APPEND);
            in=openFileInput("date5");
            writer=new BufferedWriter(new OutputStreamWriter(out));
            read = new BufferedReader(new InputStreamReader(in));
            String line="";
            while((line=read.readLine())!=null){
                StringTokenizer st = new StringTokenizer(line, ";"); //设置数据之间 的分隔符为；
                 s1 = st.nextToken();//读取的时候是 String 类
                 s2 = st.nextToken();
                if(s1.equals(i1)||s2.equals(i2)) {
                    Toast.makeText(TianjiaActivity.this, "该快捷拨号已存在", Toast.LENGTH_SHORT).show();
                    return;
                }
            }
            if(!TextUtils.isEmpty(i1)&&!TextUtils.isEmpty(i2)) {
                writer.write(i1);
                writer.write(";");
                writer.write(i2);
                writer.write(";");
                writer.newLine();
                Toast.makeText(TianjiaActivity.this, "已保存!", Toast.LENGTH_SHORT).show();
            }
        }catch(IOException e){
            e.printStackTrace();
        }finally {
            try {
                if (writer != null) {
                    writer.close();
                }
            }catch(IOException e){
                    e.printStackTrace();
                }
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.tianjia, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}