四部分:文件类型名:扩展名长度和内容 文件长度和内容
package Archive;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;public class Archiver { /** * 创建归档文件 * * @throws Exception */ public void newArchiveFile(String[] srcPaths, String yarPath) { FileOutputStream fout = null; try { // 创建yar归档文件的输出流 fout = new FileOutputStream(yarPath); for (String srcPath : srcPaths) { // 向yar归档文件中添加文件 addFile(srcPath, fout); } } catch (Exception e) { e.printStackTrace(); } finally { try { if (fout != null) { fout.close(); } } catch (IOException e) { e.printStackTrace(); } } } /** * 向yar归档文件中添加文件 * * @param srcPath * @param fout * @throws Exception */ private void addFile(String srcPath, FileOutputStream fout) { FileInputStream fin=null; try{ // 1.取出srcPath文件的类型 int fType = getFileType(srcPath); // 2.取出文件的长度 fin = new FileInputStream(srcPath); int length = fin.available(); // 将ftype写入fout byte bFtype = (byte) fType; fout.write(new byte[] { bFtype }); // 4.将长度写入yar中 byte[] bytes = IntoByteArry(length); fout.write(bytes); // 5.写入文件的内容 int len = -1; byte[] buffer = new byte[1024]; while ((len = fin.read(buffer)) != -1) { fout.write(buffer, 0, len); } }catch(Exception e) { e.printStackTrace(); } finally { try { if (fin != null) { fin.close(); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } /** * 将正数变成字节数组 * * @param length * @return */ private byte[] IntoByteArry(int i) { byte[] bytes = new byte[4]; bytes[0] = (byte) i; bytes[1] = (byte) (i >> 8); bytes[2] = (byte) (i >> 16); bytes[3] = (byte) (i >> 24); return bytes; } /** * 得到文件类型 * 0-txt * 1-jpg * 2-avi * 3-gif * 3-exe * * @param srcPath * @return */ private int getFileType(String srcPath) { // 得到扩展文件名 String ext = srcPath.substring(srcPath.lastIndexOf(".")).toLowerCase(); int type = -1; if (".txt".equals(ext)) { type = 0; } else if (".jpg".equals(ext)) { type = 1; } else if (".avi".equals(ext)) { type = 2; } else if (".gif".equals(ext)) { type = 3; } else if (".exe".equals(ext)) { type = 4; }else if(".jpeg".equals(ext)) { type=5; }else if(".yar".equals(ext)) { type=6; } return type; } /** * 添加文件到yar归档文件中 */ public void addFile(String srcPath,String yarPath) { try { FileOutputStream fos=new FileOutputStream(yarPath,true); addFile(srcPath,fos); fos.close(); } catch (Exception e) { e.printStackTrace(); } } /** * 解档文件 */ public void unarchive(String yarPath,String destDir) { FileInputStream fin=null; try { fin=new FileInputStream(yarPath); int i=1; //循环读取下一个文件 while(readNextFile(destDir,(i++)+"",fin)) { } } catch (FileNotFoundException e) { e.printStackTrace(); } finally { try { fin.close(); } catch (IOException e) { e.printStackTrace(); } } } /** * 读取下一个文件 * @param fin * @return */ private boolean readNextFile(String destDir,String fname,FileInputStream fin) { FileOutputStream fout=null; try { //文件类型 int type=fin.read(); //文件扩展名 String ext = getFileTypeExt(type); if(type==-1) { return false; } /** * 开始读取文件并写入到新文件中 */ //0.构造文件 fout=new FileOutputStream(destDir+"/"+fname+ext); //1.读取文件长度 byte[] bytes=new byte[4]; fin.read(bytes); //2.转换成字节数组成为int int fileLength=byteArryInt(bytes); //读取文件 byte[] buffer=new byte[1024]; //计算读取文件的循环次数 int count=0; if(fileLength%buffer.length==0) { count=fileLength/buffer.length; }else { count=fileLength/buffer.length+1; } //开始循环读取 for(int i=0;i package Archive;import java.io.BufferedReader;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import org.junit.jupiter.api.Test;public class App { /** * 新建归档文件 */ @Test public void newArchiveFile() { Archiver archiver=new Archiver(); String[] srcPaths= { "d:\\arch\\1.txt", "d:\\arch\\1.jpeg", "d:\\arch\\2.jpeg", "d:\\arch\\myyar.yar" }; String yarPath="d:/arch/newyar.yar"; archiver.newArchiveFile(srcPaths, yarPath); System.out.println("over!"); } /** * 向原有归档文件中添加新文件 */ @Test public void addFile() { Archiver archiver=new Archiver(); archiver.addFile("d:\\arch\\2.jpeg", "d:/arch/myyar.yar"); System.out.println("over!"); } /** *解档文件 */ @Test public void unarchiveFile() { Archiver archiver=new Archiver(); archiver.unarchive("d:/arch/newyar.yar", "d:/arch/unarch"); System.out.println("over!"); } /** * 使用文本文件存储 * @throws Exception */ @Test public void readMp3() throws Exception { FileOutputStream fos = new FileOutputStream("d:/arch/4.txt"); FileInputStream fis = new FileInputStream("d:/arch/1.jpeg"); int b = -1; while ((b = fis.read()) != -1) { fos.write((b + "").getBytes()); fos.write(new byte[] { '\t', '\n' }); ; } fos.close(); fis.close(); } /** * 使用文本文件存储 * @throws Exception */ @Test public void readMp32() throws Exception { FileWriter writer = new FileWriter("d:/arch/4.txt"); FileInputStream fis = new FileInputStream("d:/arch/1.jpeg"); int len=-1; byte[] buffer=new byte[1024]; while ((len = fis.read(buffer)) != -1) { writeByteArrTofile(buffer,0,len, writer); } writer.close(); fis.close(); } /** * 将字节数组中的字节数写入到fos中 * */ private void writeByteArrTofile(byte[] arr,int startIndex,int length,FileWriter writer) { try { for(int j=startIndex;j
package base;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.nio.charset.Charset;import org.junit.jupiter.api.Test;public class ByteStreamDemo { /** * 使用字节流复制图片 * @throws IOException */ @Test public void copyImage() throws IOException { //文件输入流(字节流) FileInputStream fin = new FileInputStream("D:\\1.jpeg"); //输出流 FileOutputStream fout = new FileOutputStream("D:\\2.jpeg",false); fin.available();//文件长度字节数 byte[] buffer=new byte[1024]; int len=-1; while(((len=fin.read(buffer))!=-1)) { fout.write(buffer,0,len); } fin.close(); fout.close(); } /** * 使用文件输出流写文本文件 * @throws Exception */ @Test public void writeFileWithFileOutputStream() throws Exception { System.out.println(Charset.defaultCharset()); String str="你好,中国人!hello world."; FileOutputStream fos=new FileOutputStream("D:\\1.txt"); fos.write(str.getBytes("utf-8")); fos.close(); System.out.println("over"); } /** * 使用文件输入流读取文件 * @throws Exception */ @Test public void readFileWithFileInputStream() throws Exception { FileInputStream fis = new FileInputStream("d:\\1.txt"); char c=(char)fis.read(); System.out.println(c); } /** * 跳过字节 * 负数-前跳,正数后跳 * @throws Exception */ @Test public void skipByteTest() throws Exception { FileInputStream fis=new FileInputStream("d:1.txt"); int c=-1; while((c=fis.read())!=-1) { fis.skip(1); System.out.println((char)c); } }} package Archive;import java.io.FileOutputStream;import java.io.RandomAccessFile;import org.junit.jupiter.api.Test;/** * 随机访问文件 * @author ASUS * */public class RandomAccessFileDemo { public static void main(String[] args) throws Exception { RandomAccessFile raf=new RandomAccessFile("d:/arch/9.txt", "rwd"); raf.write("hello world".getBytes()); //定位文件 raf.seek(3); int c=-1; while((c=raf.read())!=-1) { System.out.print((char)c); } raf.close(); System.out.println("over"); } /** * 文件内容重复 * @throws Exception */ @Test public void duplicateFile() throws Exception { RandomAccessFile raf = new RandomAccessFile("D:\\arch\\5.txt","rw"); FileOutputStream fos=new FileOutputStream("d:/arch/6.txt") ; byte[] buffer=new byte[1024]; int len=-1; while((len=raf.read(buffer))!=-1) { fos.write(buffer,0,len); } raf.seek(0); while((len=raf.read(buffer))!=-1) { fos.write(buffer,0,len); } raf.seek(0); while((len=raf.read(buffer))!=-1) { fos.write(buffer,0,len); } fos.close(); raf.close(); }} package Archive;import java.io.BufferedReader;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.InputStreamReader;import java.io.PrintStream;import org.junit.jupiter.api.Test;public class PrintStreamDemo { /** * 改变系统的out输出流向 * 默认是console * @throws Exception */ @Test public void sysoutTest() throws Exception { PrintStream ps =new PrintStream(new FileOutputStream("d:/arch/log.log")); //改变系统输出流向 System.setOut(ps); System.out.println("hello world"); } /** * 从控制台读取输入字符,打印在控制台上 * @throws Exception */ @Test public void systemin() throws Exception { //改变系统输入流向 System.setIn(new FileInputStream("d:/arch/1.txt")); BufferedReader reader=new BufferedReader(new InputStreamReader(System.in)); while(true) { String line=reader.readLine(); if("exit".equals(line)) { System.exit(-1); } System.out.println(line); } }} package Archive;import java.io.FileInputStream;import java.io.InputStream;import java.io.InputStreamReader;import org.junit.jupiter.api.Test;/** * 使用转换流,桥梁(字节-->字符) * @author ASUS * */public class InputStreamReaderDemo { /** * 使用转换流读取文本 * @throws Exception */ @Test public void read() throws Exception{ InputStreamReader reader = new InputStreamReader(new FileInputStream("D:\\arch\\4.txt"),"gbk"); char[] buffer=new char[1024]; int len=-1; while((len=reader.read(buffer))!=-1) { System.out.println(new String(buffer,0,len));; } reader.close(); } /** * 通过字节流读取文本文件的内容,观察字符数组的范围 * @throws Exception */ @Test public void readInByte() throws Exception{ FileInputStream fin = new FileInputStream("D:\\arch\\4.txt"); byte[] buffer=new byte[1024]; int len=-1; while((len=fin.read(buffer))!=-1) { System.out.println(new String(buffer,0,len));; } fin.close(); } /** * 考查System.out类 */ public void sysoutTest() { System.out.print("jfdl"); }}
package Archive;import java.io.BufferedInputStream;import java.io.FileInputStream;import org.junit.jupiter.api.Test;public class BufferedInputStreamDemo { /** * 使用缓冲区字节流读取文件 * @throws Exception */ @Test public void bufferedInputStreamTest() throws Exception { BufferedInputStream in = new BufferedInputStream(new FileInputStream("D:\\arch\\4.txt")); int i=-1; while((i=in.read())!=-1) { System.out.println(i); } in.close(); }}