java读写文件
import java.io.*;
public class Demo {
public static void main(String[] args) {
try {
// 防止文件建立或读取失败,用catch捕捉错误并打印,也可以throw
String pathname = "F:/input.txt";
InputStreamReader reader = new InputStreamReader(new FileInputStream(new File(pathname))); // 建立一个输入流对象reader
BufferedReader br = new BufferedReader(reader); // 建立一个对象,它把文件内容转成计算机能读懂的语言
/* 写入Txt文件 */
File writename = new File("F:/output.txt");
if (writename.exists()) {
writename.delete();
}
writename.createNewFile(); // 创建新文件
BufferedWriter out = new BufferedWriter(new FileWriter(writename));
String line = null;
while ((line = br.readLine()) != null) {
out.write(line + "\r\n"); // \r\n即为换行
}
out.flush(); // 把缓存区内容压入文件
out.close(); // 最后记得关闭文件
br.close();
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
//同过判断文件的结尾来读取文件
import java.io.File;
import java.io.InputStream;
import java.io.FileInputStream;
public class InputStreamDemo02
{
public static void main(String args[]) throws Exception{
File f = new File("E:"+File.separator+"java2"+File.separator+"StreamDemo"+File.separator+"test.txt");
InputStream in = new FileInputStream(f);
byte b[] = new byte[1024];
int len = 0;
int temp=0; //所有读取的内容都使用temp接收
while((temp=in.read())!=-1){ //当没有读取完时,继续读取
b[len]=(byte)temp;
len++;
}
in.close();
System.out.println(new String(b,0,len));
}
}
posted on 2018-11-05 10:29 cxhfuujust 阅读(122) 评论(0) 编辑 收藏 举报