File f = new File("文件路径");
FileInputStream fis = new FileInputStream(f);//创建一个输入流，读取f中的内容到程序中来
//System.out.println(fis.read());
byte[] b = new byte[1024];//定义一个数组，保存读取的类容
int hasRead = 0;//用 来记录读取了多长
hasRead=fis.read(b);
String s = new String(b,0,hasRead);
System.out.println(s);
热心网友| 2012-12-04 14:29

package cn.bean.demo.inoutstream;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

public class FileInputStreamTest {

    public static void main(String[] args) {
        testInputStream();
    }

    public static void testInputStream() {

        try (InputStream in = new FileInputStream("hello.txt");) {
            //用来缓存每次读取的字节数据
            byte[] buffer = new byte[10];
            //每次放入到缓冲数组中的字节个数
            int len = 0;
            String s = "";
            while ((len = in.read(buffer)) != -1) {
                s += new String(buffer, 0, len);
            }
            System.out.println(s);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

}

package cn.bean.demo.readwrite;

import java.io.FileInputStream;
import java.io.FileReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;

public class ReaderTest {
public static void main(String[] args) {
//这个会出现乱码
testFileReader();
//中文正常输出
testInputStreamReader();
}
public static void testInputStreamReader(){
//，InputStreamReader 将字节流转换为字符流。是字节流通向字符流的桥梁。如果不指定字符集编码，该解码过程将使用平台默认的字符编码，如：GBK。 InputStreamReader的构造器指定只能接收InputStream类型
try ( InputStream in=new FileInputStream("hello.txt");
Reader read=new InputStreamReader(in,"UTF-8");){

//用来缓存每次读取的字符数据
char[] c=new char[10];

//每次放入到缓冲数组中的字符个数
int len=0;
String s="";
while((len=read.read(c))!=-1){
s+= new String(c,0,len);
}
System.out.println(s);
} catch (Exception e) {
e.printStackTrace();
}

}
public static void testFileReader(){

try (
Reader read=new FileReader("hello.txt");){

//用来缓存每次读取到的字符
char[] c=new char[10];

//每次放入缓冲数组中的字符个数
int len=0;
String s="";
while((len=read.read(c))!=-1){
s+= new String(c,0,len);
}
System.out.println(s);
} catch (Exception e) {
e.printStackTrace();
}

}
}