1、在io包中，提供了两个与平台无关的数据操作流
数据输出流（DataOutputStream）
数据输入流（DataInputStream）
2、通常数据输出流会按照一定的格式将数据输出，再通过数据输入流按照一定的格式将数据读入
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（1）DataOutputStream
package org.example.io;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
public class TestDataOutputStream {
public static void main(String[] args) throws IOException {
DataOutputStream dos = null;
File f = new File("e:\\s\\test\\a.txt");
dos = new DataOutputStream(new FileOutputStream(f));
String[] name = {"衬衫", "手套", "围巾"};
float[] price = {98.3f, 30.3f, 50.5f};
int[] num = {3, 2, 1};
for (int i = 0; i < name.length; i++) {
dos.writeChars(name[i]);
dos.writeChar('\t');
dos.writeFloat(price[i]);
dos.writeChar('\t');
dos.writeInt(num[i]);
dos.writeChar('\n');
}
dos.flush();
dos.close();
}
}
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（2）DataInputStream
package org.example.io;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
public class TestDataInputStream {
public static void main(String[] args) {
DataInputStream dis = null;
File f = new File("e:\\s\\test\\a.txt");
try {
dis = new DataInputStream(new FileInputStream(f));
String name = null;
float price = 0.0f;
int num = 0;
char[] temp = null; /* 接收商品名称 */
int len = 0; /* 保存读取数据的个数 */
char c = 0; /* '\u0000' */
while (true) {
temp = new char[200];
len = 0;
while ((c = dis.readChar()) != '\t') { /* 单个字符地循环读取商品名称 */
temp[len] = c;
len++;
}
name = new String(temp, 0, len); /* 商品名称 */
price = dis.readFloat(); /* 读取价格 */
dis.readChar(); /* 读取\t */
num = dis.readInt(); /* 读取数量 */
dis.readChar(); /* 读取\n */
System.out.println("Name:"+name+"\t\tPrice:"+price+"\tNum:"+num);
}
} catch (FileNotFoundException e2) {
e2.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (dis != null) {
try {
dis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}