获取android的SDK或者手机目录路径

Google为我们提供了API来获取SDK或者手机目录路径：

1、获取SD卡目录

　　File file1 = Environment.getExternalStorageDirectory();

2、获取手机内部存储空间的file目录

　　File file2 = getFilesDir();

3、获取内部存储空间的缓存目录

　　File file3 = getCacheDir();

4、检查SD是否被挂载

　　String state = Environment.getExternalStorageState();

　　如果 state==“mounted” 表示被挂载

 

代码：

com.example.readwrite.MainActivity

package com.example.readwrite;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;

/**
 * 正斜杠代表根目录 两种最常见的数据存储方式
 * 
 * 一、内存 二、本地 1.手机内部存储 2.外部存储设备（SD卡）
 * */
public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // existSDcard();
        // write();
        listPath();
        //read();
    }

    private void write() {
        // /mnt/sdcard
        File file = Environment.getExternalStorageDirectory();
        FileOutputStream out = null;
        try {
            out = new FileOutputStream(file.getPath() + "/fanfan.txt");
            // out = new FileOutputStream(
            // "/data/data/com.example.readwrite/fanfan.txt");
            out.write("12345".getBytes());
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (out != null) {
                try {
                    out.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }

    private void read() {
        FileInputStream in = null;
        try {
            // in = new FileInputStream("/mnt/sdcard/fanfan.txt");
            in = new FileInputStream(
                    "/data/data/com.jiguang.test/databases/rep.db");
            byte[] bytes = new byte[2014];
            int len = in.read(bytes);
            String str = new String(bytes, 0, len);
            Log.d("fanfan", "---------" + str);
        } catch (IOException e) {
            Log.d("fanfan","报错啦"+e.toString());
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    /**
     * 检查SD卡是否被挂载
     * */
    private void existSDcard() {
        // 获取SD卡的状态
        String state = Environment.getExternalStorageState();

        if (Environment.MEDIA_MOUNTED.equals(state)) {
            Log.d("fanfan", "有SD卡");
        } else {
            Log.d("fanfan", "没有SD卡");
        }
    }

    /**
     * 通过API获取路径
     * */
    private void listPath() {
        // 获取SD卡目录
        File file1 = Environment.getExternalStorageDirectory();
        Log.d("fanfan", "sd卡----" + file1.getPath());
        // 获取手机内部存储空间的file目录
        File file2 = getFilesDir();
        Log.d("fanfan", "内部存储File----" + file2.getPath());
        // 获取内部存储空间的缓存目录
        File file3 = getCacheDir();
        Log.d("fanfan", "内部存储缓存目录----" + file3.getPath());
    }
}

    /**
     * 检查SD卡是否被挂载
     * */
    private void existSDcard() {
        // 获取SD卡的状态
        String state = Environment.getExternalStorageState();

        if (Environment.MEDIA_MOUNTED.equals(state)) {
            Log.d("fanfan", "有SD卡");
        } else {
            Log.d("fanfan", "没有SD卡");
        }
    }