读取与保存

数据存储的效果

package com.zking.administrator.myapplication10;import android.content.Context;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;public class MainActivity extends AppCompatActivity {private EditText et_main_content;private EditText et_main_name;private String sdCard;&＃64;Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);et_main_content &＃61; (EditText) findViewById(R.id.et_main_content);et_main_name &＃61; (EditText) findViewById(R.id.et_main_name);//获取手机卡的路径if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){sdCard &＃61; Environment.getExternalStorageDirectory().getAbsolutePath();}}public void save(View view){//拿到文件的名字String fileName&＃61;et_main_name.getText().toString();//拿到内容String content&＃61;et_main_content.getText().toString();//io写&＃xff0c;输出流 "fileName"文件的名字&＃xff0c;"Context.MODE_PRIVATE"文件的类型try {//openFileOutput是系统自带的方法//FileOutputStream fos&＃61;openFileOutput(fileName, Context.MODE_PRIVATE);FileOutputStream fos&＃61;new FileOutputStream(sdCard&＃43;"/"&＃43;fileName);//保存到内存卡里了fos.write(content.getBytes());fos.close();Toast.makeText(this, "保存成功", Toast.LENGTH_SHORT).show();} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}public void read(View view){//拿到文件的名字String fileName&＃61;et_main_name.getText().toString();//读&＃xff0c;输入流try {//FileInputStream fis&＃61;openFileInput(fileName);FileInputStream fis&＃61;new FileInputStream(sdCard&＃43;"/"&＃43;fileName);byte buf[]&＃61;new byte[1024];int len&＃61;0;StringBuffer sb&＃61;new StringBuffer();while((len&＃61;fis.read(buf))!&＃61;-1){sb.append(new String(buf,0,len));}et_main_content.setText(sb);fis.close();Toast.makeText(this, "打开", Toast.LENGTH_SHORT).show();} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}
}