IOの数据流

以你之姓@ 2022-08-22 05:53 204阅读 0赞

</pre><pre code_snippet_id="1696412" snippet_file_name="blog_20160525_2_8740433" name="code" class="java">

package IO;
    
    import java.io.DataInput;
    import java.io.DataInputStream;
    import java.io.DataOutputStream;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.PrintStream;
    
    import javax.xml.crypto.Data;
    
    import org.junit.Test;
    
    public class TestOtherStream {
    
    	@Test
    	public void TestData() {
    		DataInputStream dataInput = null;
    		try {
    			dataInput = new DataInputStream(new FileInputStream(new File("data.txt")));
    //			byte[] bs = new byte[20];
    //			int len;
    //			while ((len = dataInput.read(bs)) != -1) {
    //
    //				System.out.println(new String(bs, 0, len));
    //			}
    			String string=dataInput.readUTF();
    			System.out.println(string);
    		} catch (FileNotFoundException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		} catch (IOException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		} finally {
    			if (dataInput != null) {
    				try {
    					dataInput.close();
    				} catch (IOException e) {
    					// TODO Auto-generated catch block
    					e.printStackTrace();
    				}
    			}
    		}
    
    	}
    
    	// 数据流：处理基本数据类型、String、字节数组的数据
    	// DataInputStream和DataOutputStream,分别套接在InputStream和OutputStream节点流上
    	// 没有reader和writer因为不是文本
    	@Test
    	public void Data() {
    		DataOutputStream dataOutputStream = null;
    		try {
    			FileOutputStream fileOutputStream = new FileOutputStream("data.txt");
    			dataOutputStream = new DataOutputStream(fileOutputStream);
    			dataOutputStream.writeUTF("I love u but u dont know ！");
    			dataOutputStream.writeBoolean(true);
    			dataOutputStream.writeLong(34153454);
    
    		} catch (IOException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		} finally {
    			if (dataOutputStream != null) {
    				try {
    					dataOutputStream.close();
    				} catch (IOException e) {
    					// TODO Auto-generated catch block
    					e.printStackTrace();
    				}
    
    			}
    		}
    
    	}
    
    	// 打印流：字节流PrintStream字符流PrintWriter
    	@Test
    	public void printStreamWriter() {
    		FileOutputStream fileOutputStream = null;
    		try {
    			fileOutputStream = new FileOutputStream(new File("print.txt"));
    		} catch (FileNotFoundException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    
    		// 创建打印输出流，设置为自动刷新模式（写入换行符或字节'\n',时会刷新输出缓冲区）
    		PrintStream pStream = new PrintStream(fileOutputStream, true);
    
    		// 把标准输出流（控制台输出）改成文件输出
    		if (pStream != null) {
    			System.setOut(pStream);
    		}
    
    		for (int i = 0; i < 255; i++) {
    			System.out.print((char) i);// 输出ASCII字符
    			if (i % 50 == 0) {
    				System.out.println();// 每50个数据换行
    			}
    		}
    		pStream.close();
    	}
    
    }