Android学习笔记（七）输出流Log、download、写入SDCard
一、输出流Log

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package mars.utils;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import android.os.Environment;public class FileUtils {private String SDPATH;public String getSDPATH() {return SDPATH;}public FileUtils() {//得到当前外部存储设备的目录// /SDCARDSDPATH = Environment.getExternalStorageDirectory() + "/";}/** * 在SD卡上创建文件 * * @throws IOException */public File creatSDFile(String fileName) throws IOException {File file = new File(SDPATH + fileName);file.createNewFile();return file;}/** * 在SD卡上创建目录 * * @param dirName */public File creatSDDir(String dirName) {File dir = new File(SDPATH + dirName);dir.mkdirs();return dir;}/** * 判断SD卡上的文件夹是否存在 */public boolean isFileExist(String fileName){File file = new File(SDPATH + fileName);return file.exists();}/** * 将一个InputStream里面的数据写入到SD卡中 *///三个参数：路径、文件名、输入流里的数据public File write2SDFromInput(String path,String fileName,InputStream input){File file = null;OutputStream output = null;try{creatSDDir(path);//根据路径和文件名来创建文件file = creatSDFile(path + fileName);//根据这个文件对象创建一个FileOutputStream对象，写入数据output = new FileOutputStream(file);byte buffer [] = new byte[4 * 1024];while((input.read(buffer)) != -1){output.write(buffer);}//清空缓存output.flush();}catch(Exception e){e.printStackTrace();}finally{try{output.close();}catch(Exception e){e.printStackTrace();}}return file;}}?

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