Android保存文件到SDCard

Service方法

......
public class FileService {
    private static String TAG = "FileManager";
    private Context context;

    ......
    
    /**
     * 向SDCard中写文件
     * @param name
     * @param content
     * @throws Exception
     */
    public void saveFileToSDCard(String fileName, String content) throws Exception {
        //检验手机是否存在SDCard， SDCard是否是写保护的
        if(!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            throw new Exception("SDCard不存在或是写保护的");
        }
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(new File(Environment.getExternalStorageDirectory(), fileName));
            fos.write(content.getBytes());
        } catch (Exception e) {
            throw new Exception(e);
        } finally {
            if(fos != null) {
                fos.close();
            }
        }
    }
    
    public String readFileFromSDCard(String fileName) throws Exception {
        //检验手机是否存在SDCard， SDCard是否是写保护的
        if(!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED) && 
                !Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED_READ_ONLY)) {
            throw new Exception("SDCard不存在或是不可读");
        }
        FileInputStream fis = null;
        String content = null;
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        try {
            fis = new FileInputStream(new File(Environment.getExternalStorageDirectory(), fileName));
            byte[] buffer = new byte[1024];
            int length = 0;
            while((length = fis.read(buffer)) >= 0) {
                os.write(buffer, 0, length);
            }
            content = new String(os.toByteArray());
        } catch (Exception e) {
            throw new Exception(e);
        } finally {
            if(fis != null) {
                fis.close();
            }
            if(os != null) {
                os.close();
            }
        }
        return content;
    }

    public Context getContext() {
        return context;
    }

    public void setContext(Context context) {
        this.context = context;
    }
    
}

 activity中调用

        Button saveToSDCardBtn = (Button) findViewById(R.id.save_to_sdcard_btn_view);
        saveToSDCardBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String fileName = fileNameView.getText().toString();
                String content = fileContentView.getText().toString();
                try {
                    fileService.saveFileToSDCard(fileName, content);
                } catch (Exception e) {
                    Toast.makeText(getApplicationContext(), R.string.save_fail, Toast.LENGTH_SHORT).show();
                    e.printStackTrace();
                }
                Toast.makeText(getApplicationContext(), R.string.save_successful, Toast.LENGTH_SHORT).show();
            }
        });

 

因为读写SDCard不是一个安全的行为，所以要在清单文件中配置一些权限

    <!-- 往SDCard创建和删除文件的权限 -->
    <uses-permission 
        android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
    <!-- 往SDCard中写东西的权限 -->
    <uses-permission 
        android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

 

然后就可以进行测试了。