Android在内存中读取数据

Android在内存中读取数据package com.itheima.rwinrom;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStreamReader;

import org.apache.http.entity.InputStreamEntity;

import android.os.Bundle;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {

private EditText et_name;
private EditText et_pass;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

et_name = (EditText) findViewById(R.id.et_name);
et_pass = (EditText) findViewById(R.id.et_pass);

readAccount();

}

public void readAccount(){
File file = new File("data/data/com.itheima.rwinrom/info.txt");
if(file.exists()){
try {
FileInputStream fis = new FileInputStream(file);
//把字节流转换成字符流
BufferedReader br = new BufferedReader(new InputStreamReader(fis));
//读取txt文件里的用户名和密码
String text = br.readLine();
String[] s = text.split("##");

et_name.setText(s[0]);
et_pass.setText(s[1]);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

public void login(View v){

String name = et_name.getText().toString();
String pass = et_pass.getText().toString();

CheckBox cb = (CheckBox) findViewById(R.id.cb);
//判断选框是否被勾选
if(cb.isChecked()){
//data/data/com.itheima.rwinrom:这就是内部存储空间的路径
File file = new File("data/data/com.itheima.rwinrom/info.txt");
FileOutputStream fos;
try {
fos = new FileOutputStream(file);
fos.write((name + "##" + pass).getBytes());
fos.close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

//创建并显示吐司对话框
Toast.makeText(this, "登录成功", 0).show();
}

}

用API在内存中读取数据

package com.itheima.rwinrom;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStreamReader;

import org.apache.http.entity.InputStreamEntity;

import com.itheima.apirwinrom.R;

import android.os.Bundle;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {

private EditText et_name;
private EditText et_pass;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

et_name = (EditText) findViewById(R.id.et_name);
et_pass = (EditText) findViewById(R.id.et_pass);

readAccount();

}

public void readAccount(){
// File file = new File(getFilesDir(), "info.txt");
File file = new File(getCacheDir(), "info.txt");
if(file.exists()){
try {
FileInputStream fis = new FileInputStream(file);
//把字节流转换成字符流
BufferedReader br = new BufferedReader(new InputStreamReader(fis));
//读取txt文件里的用户名和密码
String text = br.readLine();
String[] s = text.split("##");

et_name.setText(s[0]);
et_pass.setText(s[1]);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

public void login(View v){

String name = et_name.getText().toString();
String pass = et_pass.getText().toString();

CheckBox cb = (CheckBox) findViewById(R.id.cb);
//判断选框是否被勾选
if(cb.isChecked()){
//返回一个File对象，其路径是data/data/com.itheima.apirwinrom/files
// File file = new File(getFilesDir(), "info.txt");

//返回值也是一个File对象，其路径是data/data/com.itheima.apirwinrom/cache
File file = new File(getCacheDir(), "info.txt");
FileOutputStream fos;
try {
fos = new FileOutputStream(file);
fos.write((name + "##" + pass).getBytes());
fos.close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

//创建并显示吐司对话框
Toast.makeText(this, "登录成功", 0).show();
}

}