java IO流练习:文件复制、遍历子目录、复制所有子目录

import org.junit.Test;

import java.awt.*;
import java.io.*;
import java.net.URI;
import java.net.URISyntaxException;
import java.text.SimpleDateFormat;

/**
* @author king
*         Created by king on 2017/5/19.
*/
public class IOTrain {
//    @Test
public void testTime() {//测试函数运行时间
long start = System.currentTimeMillis();
for (int i = 0; i < 1; i++) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
long end = System.currentTimeMillis();
SimpleDateFormat sdf = new SimpleDateFormat("s");
System.out.println(sdf.format(end - start));
}

//    @Test
public void createFile() {//创建a.txt
File file = new File("D:\\file\\a.txt");
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
}

//    @Test
public void fileList() {//列出D盘下的所有文件、文件夹
File file = new File("D:");
String[] ss = file.list();
for (String s : ss) System.out.println(s);
}

//    @Test
public void fileList2() {//列出D盘下的所有文件、文件夹
File
4000
file = new File("D:");
File[] files = file.listFiles();
for (File f : files) System.out.println(f.getPath());
}

//    @Test
public void makeDir() {//创建文件夹
File file = new File("D:\\file\\44");
file.mkdir();
}

//    @Test
public void testShowAllDir() {//显示D盘下所有的子文件
String path = "D:";
showAllDir(path);
}

public void showAllDir(String path) {
File file = new File(path);
File fs[] = file.listFiles();
for (int i = 0; i < fs.length; i++) {
if (fs[i].isDirectory()) {
try {
showAllDir(fs[i].getAbsolutePath());
} catch (Exception e) {
}
} else {
System.out.println(fs[i].getAbsolutePath());
}
}
}

//    @Test
public void browseBaidu1() {//用浏览器打开百度
try {
URI uri = new URI("http://www.baidu.com");
Desktop.getDesktop().browse(uri);
} catch (Exception e) {
}
}

//    @Test
public void browseBaidu2() {//用浏览器打开百度，完整版
String webSite = "http://www.baidu.com";
Desktop desktop = Desktop.getDesktop();
if (Desktop.isDesktopSupported() && desktop.isSupported(Desktop.Action.BROWSE)) {
URI uri = null;
try {
uri = new URI(webSite);
} catch (URISyntaxException e) {
e.printStackTrace();
}
try {
desktop.browse(uri);
} catch (IOException e) {
e.printStackTrace();
}
}
}

//    @Test
public void readByte() {// 从文件系统中的某个文件中获得输入字节
try (FileInputStream fs = new FileInputStream("D:\\file\\1.txt")) {
byte[] buffer = new byte[1024];
int n = 0;
while ((n = fs.read(buffer)) != -1) {
System.out.println(new String(buffer));
}
} catch (IOException e) {
e.printStackTrace();
}
}

@Test
public void writeByte() {//FileOutputStream，意为文件输出流，是用于将数据写入File或 FileDescriptor的输出流。
try (FileOutputStream fs = new FileOutputStream("D:\\file\\3.txt")) {
fs.write("哈尔滨".getBytes());
} catch (IOException e) {
e.printStackTrace();
}
}

//    @Test
public void copyByte() {//将1.txt拷贝到2.txt
try (FileOutputStream w = new FileOutputStream("D:\\file\\2.txt");
FileInputStream r = new FileInputStream("D:\\file\\1.txt")) {
byte[] buffer = new byte[1024];
int n = 0;
while ((n = r.read(buffer)) != -1) {
w.write(buffer, 0, n);
}
} catch (IOException e) {
e.printStackTrace();
}
}

//    @Test
public void readChar() {//FileReader类从InputStreamReader类继承而来。该类按字符读取流中数据。
try (Reader reader = new FileReader("D:\\file\\1.txt")) {
char[] buffer = new char[20];
int n = 0;
while ((n = reader.read(buffer)) != -1) {
System.out.println(buffer);
}
} catch (IOException e) {
e.printStackTrace();
}
}

//    @Test
public void writeChar() {//FileWriter类从OutputStreamReader类继承而来。该类按字符向流中写入数据。
try (Writer writer = new FileWriter("D:\\file\\1.txt")) {
writer.write("哈尔滨");
} catch (IOException e) {
e.printStackTrace();
}
}

//    @Test
public void copyChar() {//按字符流将1.txt复制给2.txt
try (FileReader reader = new FileReader("D:\\file\\1.txt");
FileWriter writer = new FileWriter("D:\\file\\2.txt")) {
int n = 0;
char[] buffer = new char[20];
while ((n = reader.read(buffer)) != -1) {
writer.write(buffer, 0, n);
}
} catch (IOException e) {
e.printStackTrace();
}
}

//    @Test
public void FindFileByType() {//查找 *.bat
File file = new File("D:");
File[] find = file.listFiles(new FilenameFilter() {
@Override
public boolean accept(File dir, String name) {
return name.endsWith(".bat");
}
});
for (File f : find) System.out.println(f.getName());
}

//    @Test
public void testCopyAllDir1() {
String readPath = "D:\\file";//源地址
String writePath = "D:\\file2";//目标地址
new File(writePath).mkdirs();
copyAllDir1(readPath, writePath);
}

public void copyAllDir1(String readPath, String writePath) {
File file = new File(readPath);
File[] fs = file.listFiles();
for (int i = 0; i < fs.length; i++) {
try {
if (fs[i].isDirectory()) {
fs[i].mkdir();
copyAllDir1(fs[i].getAbsolutePath(), writePath + "\\" + fs[i].getName());
} else {
System.out.println(fs[i].getAbsolutePath());
}
} catch (Exception e) {
}
}
}

//    @Test
public void testCopyAllDir2() {
String readPath = "D:\\file";//源地址
String writePath = "D:\\file2";//目标地址
new File(writePath).mkdir();
copyAllDir2(readPath, writePath);
}

public void copyAllDir2(String readPath, String writePath) {//将readPath中的所有子文件拷贝到writePath目录下。
//获取当前readPath目录下所有文件、文件夹，并存在fs[] 中
File file = new File(readPath);
File fs[] = file.listFiles();

//fs!=null 排除空指针异常
if (fs != null) {
//遍历当前目录
for (int i = 0; i < fs.length; i++) {
//如果当前对象fs[i]是文件夹，则在目标地址中创建同名的文件夹。
if (fs[i].isDirectory()) {
new File(writePath + "\\" + fs[i].getName()).mkdir();
copyAllDir2(fs[i].getPath(), writePath + "\\" + fs[i].getName());
}

//如果当前对象fs[i]是文件，那么按字节拷贝到目标地址。
else {
try (FileInputStream readFile = new FileInputStream(fs[i].getPath());/*从这里读数据*/
FileOutputStream writeFile = new FileOutputStream(writePath + "\\" + fs[i].getName()))/*往这里写数据*/ {
byte[] buffer = new byte[1024];
int n = 0;
while ((n = readFile.read(buffer)) != -1) {
writeFile.write(buffer, 0, n);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}

//    @Test
public void mergeRandomAccessFile() {//将两个mp3文件合并。RandomAccessFile的唯一父类是Object
try (RandomAccessFile r = new RandomAccessFile("c://1.mp3", "r");
RandomAccessFile w = new RandomAccessFile("c://2.mp3", "rw")) {
byte[] buffer = new byte[1024 * 1024];
w.seek(1024 * 1024);//定位到末尾，MP3 avi
int n = 0;
while ((n = r.read(buffer)) != -1) {
w.write(buffer, 0, n);
}
} catch (Exception e) {
e.printStackTrace();
}
}

//    @Test
public void copyRandomAccessFile() {//复制文件。RandomAccessFile已经被JDK1.4的nio的"内存映射文件(memory-mapped files)"给取代了。
try (RandomAccessFile r = new RandomAccessFile("c://1.wmv", "r");
RandomAccessFile w = new RandomAccessFile("d://2.wmv", "rw")) {
byte[] buffer = new byte[1024 * 1024];
int n = 0;
while ((n = r.read(buffer)) != -1) {
w.write(buffer, 0, n);
}
} catch (Exception e) {
e.printStackTrace();
}
}

//    @Test
public void divideRandomAccessFile(){//将1.txt分割为多个
try(RandomAccessFile r=new RandomAccessFile("D:\\file\\1.txt","r")){
byte[] buffer=new byte[2];
int n=0;
int i=1;
while((n=r.read(buffer))!=-1){
RandomAccessFile w=new RandomAccessFile("D:\\file\\1_"+(i++)+".txt","rw");
w.write(buffer,0,n);
}
}catch (IOException e) {
e.printStackTrace();
}
}

@Test
public void mergeFile(){//将多个1_?.txt文件合并为一个1.txt文件
File file=null;
try(RandomAccessFile w=new RandomAccessFile("D:\\file\\1.txt","rw")){
int i=1;
while((file=new File("D:\\file\\1_"+(i++)+".txt")).exists()){
RandomAccessFile r=new RandomAccessFile(file,"r");
copyTo(r,w);
}
}catch(IOException e){e.printStackTrace();}
}

private void copyTo(RandomAccessFile r, RandomAccessFile w) throws IOException {
byte[] buffer=new byte[8];
int n=0;
while((n=r.read(buffer))!=-1){
w.write(buffer,0,n);
}
}
}