Java学習のIOフロー

1.FilenameFilterインタフェースを実現し、accept法を適用して指定ディレクトリの下のすべての条件に合致するファイルを遍歴し、ここですべてを遍歴する.JAvaファイルの例:
 
 

import java.io.File;
import java.io.FilenameFilter;

public class File_list_accept {
	/**
	 * Main   ，    
	 * @param args
	 */
	public static void main(String[] args) {
		File file = new File(".");
		File[] nameList = file.listFiles(new MyFilenameFilter());		
		for (File name : nameList) {
			if (name.getAbsoluteFile().isDirectory()) {
				File[] nameListFiles = name.listFiles(new MyFilenameFilter());
				for (File name1 : nameListFiles) {
					System.out.println(name1.getName());
				}
			}
		}
	}

}

class MyFilenameFilter implements FilenameFilter {

	@Override
	public boolean accept(File dir, String name) {
		return name.endsWith(".java")||new File(name).isDirectory();
	}

}

 
 
2.PrintStream類の練習
 

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.PrintStream;

public class PrintStreamText {
	public static void main(String[] args) throws FileNotFoundException {
		PrintStream printStream = null;
		FileOutputStream fos = new FileOutputStream("printStream.txt");
		printStream = new PrintStream(fos);
		printStream.println("Java       PrintStream      ");
		printStream.print(new PrintStreamText());
		printStream.close();
		//             PrintStream  ，     FileOutputSream
		//                 ，                  
	}
}

 
 
 
3.入力ストリームFileInputStreamとFileReader
 

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;


public class Read_FileInputStream_and_FileReader {
	
	public static void main(String[] args) {
		Read_FileInputStream_and_FileReader file = new Read_FileInputStream_and_FileReader();
//		file.fileInputSreamMethod();
		file.fileReaderMethod();
	}
	
	/**
	 *           
	 */
	public void fileInputSreamMethod(){
		FileInputStream fileInputStream = null;
		try {
			//     
//			fileInputStream = new FileInputStream("D:\\D\\Android_Code\\Java_IO_(1)\\src\\File.java");
			fileInputStream = new FileInputStream("./src/File_list_accept.java");
			byte[] bytes = new byte[1024];//          1 ，     “    ”      ，
			//             2   ， read               ，      
			int readCount  = 0;
			while ((readCount  = fileInputStream.read(bytes)) > 0) {
				System.out.println(new String(bytes, 0, readCount));
			}
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
				if (fileInputStream != null) {
					try {
						fileInputStream.close();
					} catch (IOException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				}
		}
	}
	
	/**
	 *          
	 */
	public void fileReaderMethod(){
		FileReader fileReader = null;
		try {
			fileReader = new FileReader("./src/File_list_accept.java");
//			fileReader.skip(200);
			char[] chars = new char[1024];
			int readCount = 0;
			while ((readCount = fileReader.read(chars)) > 0) {
				System.out.println(new String(chars, 0, readCount));
			}
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			if (fileReader != null) {
				try {
					fileReader.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
		
	}
	
}

 
 
 
4.出力ストリームFileOutputStreamとFileWriter
 

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


public class Write_FileOutputStream_and_FileWriter {
	public static void main(String[] args) throws IOException {
		/**
		 * FileInputStream
		 */
		FileInputStream fileInputStream = null;
		FileOutputStream fileOutputStream = null;
		fileInputStream = new FileInputStream("./src/File_list_accept.java");
		fileOutputStream = new FileOutputStream("newFile.txt");
		byte[] bytes = new byte[1024];
		int readCount = 0;
		while ((readCount = fileInputStream.read(bytes)) > 0) {
			fileOutputStream.write(bytes, 0, readCount);
		}
		if (fileInputStream != null) {
			fileInputStream.close();
		}
		if (fileOutputStream != null) {
			fileOutputStream.close();
		}
		
		/**
		 * FileWriter
		 */
		FileWriter fileWriter = null;
		fileWriter = new FileWriter("./fileWriter.txt");
		fileWriter.write("---------   ---------\r
"); 
		// \r
 Window    ，Linux   
  
		fileWriter.write("     ，     。\r
");
		fileWriter.write("     ，     。");
		if (fileWriter != null) {
			fileWriter.close();
		}
	}
}