import java.io.*;public class abc{
public static void main( String[] args ) throws Exception{
BufferedReader br =new BufferedReader( new FileReader( "abc.java " ) );
BufferedWriter bw = new BufferedWriter( new FileWriter( "abc.java " ) );
String s = br.readLine();
br.close();
String w = "abc.java";
bw.write( w );
}
}
public static void main( String[] args ) throws Exception{
BufferedReader br =new BufferedReader( new FileReader( "abc.java " ) );
BufferedWriter bw = new BufferedWriter( new FileWriter( "abc.java " ) );
String s = br.readLine();
br.close();
String w = "abc.java";
bw.write( w );
}
}
bw.write( w );
后面加上一句
bw.close();
BufferedWriter write = new BufferedWriter(new FileWriter(file));
String str = "lajdogfjawoij;asoidf";
write.write(str,0,str.length());
write.flush();
write.close();BufferedReader read = new BufferedReader(new FileReader(file));
String str2 = null;
while((str2 = read.readLine())!=null){
System.out.println(str2);
}
read.close();
等 级: ^^^^
四条内裤的老大啊
import java.lang.*;
public class ReadFile
{
public static void main(String args[]) throws Exception
{
FileReader br=new FileReader("test.txt");
PrintWriter bw=new PrintWriter(new FileWriter("www.txt"));
char s;
String ss;
int t;
while(br.ready()){
t=br.read();
char c;
c=(char)t;
ss=s+"";
bw.write(s);
bw.flush();
}
}
}
import java.io.*;
import java.sql.*;
import java.util.*;
import javax.servlet.*;
//import javax.servlet.http.*;/**
*提取参数的通用类*@author aa
*Made in Zhengzhou.ha.china
*datetime 2002.5.23
*/
public class GetIni{/**
*定义提取参数的通用方法
*@param ininame 配置名称
*@return 执行成功返回配置内容 否则返回"error"
*/
public String getini(String ininame){
InputStream is = getClass().getResourceAsStream("/gkgl/basic/db.properties");
Properties dbProps = new Properties();
try {
dbProps.load(is);
}catch (Exception e) {
System.err.println("不能读取属性文件. " + "请确保db.properties在CLASSPATH指定的路径中");
return "error";
}//end try
String iniString = dbProps.getProperty(ininame, "DBConnectionManager.log");
return iniString;
}//end public getini/**
*定义提取数据库连接参数的通用方法
*@param ininame 配置名称
*@return 执行成功返回配置内容(数组型:Url,Conn,User,PassWd) 否则返回"error"
*/
public String[] GetDatainis(String ininame){
String[] iniString = new String[4];
InputStream is = getClass().getResourceAsStream("/gkgl/basic/db.properties");
Properties dbProps = new Properties();
try {
dbProps.load(is);
}catch (Exception e) {
System.err.println("不能读取属性文件. " + "请确保db.properties在CLASSPATH指定的路径中");
iniString = null;
return iniString;
}//end try
iniString[0] = dbProps.getProperty(ininame+".Url", "reading error");
iniString[1] = dbProps.getProperty(ininame+".Conn", "reading error");
iniString[2] = dbProps.getProperty(ininame+".User", "reading error");
iniString[3] = dbProps.getProperty(ininame+".PassWd", "reading error");
return iniString;
}//end public getini /**
* 提取指标代码对应的该指标税务机关汇总结果URL
* @param config ServletConfig
* @filename 需要载入的文本文件名
* @return Properties类型的值
*/
public Properties getZbdmSwjghz(ServletConfig config,String filename) {
try {
String absPath=config.getServletContext().getRealPath("/property_files/"+filename);
FileInputStream fis=new FileInputStream(absPath);
Properties p=new Properties();
p.load(fis);
return p;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}}
not only read
but also writeWhy not use RandomAccessFile ??somebody write a sample code,please!
import java.util.*;class ModifyFileContent {
public static void main(String[] args) throws IOException {
String pwd = "222";
String modifiedLine = "";
String line = "";
RandomAccessFile file = new RandomAccessFile("user.txt", "rw");
long fileOffset = file.getFilePointer(); while ( (line = file.readLine()) != null) {
StringTokenizer st = new StringTokenizer(line); while (st.nextToken().equals("c")) {
modifiedLine += "a" + " " + st.nextToken() + " " + pwd;
System.out.println(modifiedLine);
file.seek(fileOffset);
file.writeBytes(modifiedLine);
}
fileOffset = file.getFilePointer();
} }
}/*user.txt的内容是
a 1 111
b 2 222
c 3 333
*/以上程序可以修改最后的333为222