总结四个这几天遇到的知识点

1、先分享一个类： 用于文件操作的，使用很方便
例如：
FileOperate fo=new FileOperate();
fo.copyFile("c:/1.txt","d:/1.txt");
import java.io.*;
public class FileOperate {
public FileOperate() {
}
/**
* 新建目录
* @param folderPath String 如 c:/fqf
* @return boolean
*/
public void newFolder(String folderPath) {
try {
String filePath = folderPath;
filePath = filePath.toString();
java.io.File myFilePath = new java.io.File(filePath);
if (!myFilePath.exists()) {
myFilePath.mkdir();
}
}
catch (Exception e) {
System.out.println("新建目录操作出错");
e.printStackTrace();
}
}
/**
* 新建文件
* @param filePathAndName String 文件路径及名称 如c:/fqf.txt
* @param fileContent String 文件内容
* @return boolean
*/
public void newFile(String filePathAndName, String fileContent) {
try {
String filePath = filePathAndName;
filePath = filePath.toString();
File myFilePath = new File(filePath);
if (!myFilePath.exists()) {
myFilePath.createNewFile();
}
FileWriter resultFile = new FileWriter(myFilePath);
PrintWriter myFile = new PrintWriter(resultFile);
String strContent = fileContent;
myFile.println(strContent);
resultFile.close();
}
catch (Exception e) {
System.out.println("新建目录操作出错");
e.printStackTrace();
}
}
/**
* 删除文件
* @param filePathAndName String 文件路径及名称 如c:/fqf.txt
* @param fileContent String
* @return boolean
*/
public void delFile(String filePathAndName) {
try {
String filePath = filePathAndName;
filePath = filePath.toString();
java.io.File myDelFile = new java.io.File(filePath);
myDelFile.delete();
}
catch (Exception e) {
System.out.println("删除文件操作出错");
e.printStackTrace();
}
}
/**
* 删除文件夹
* @param filePathAndName String 文件夹路径及名称 如c:/fqf
* @param fileContent String
* @return boolean
*/
public void delFolder(String folderPath) {
try {
delAllFile(folderPath); //删除完里面所有内容
String filePath = folderPath;
filePath = filePath.toString();
java.io.File myFilePath = new java.io.File(filePath);
myFilePath.delete(); //删除空文件夹
}
catch (Exception e) {
System.out.println("删除文件夹操作出错");
e.printStackTrace();
}
}
/**
* 删除文件夹里面的所有文件
* @param path String 文件夹路径 如 c:/fqf
*/
public void delAllFile(String path) {
File file = new File(path);
if (!file.exists()) {
return;
}
if (!file.isDirectory()) {
return;
}
String[] tempList = file.list();
File temp = null;
for (int i = 0; i < tempList.length; i++) {
if (path.endsWith(File.separator)) {
temp = new File(path + tempList[i]);
}
else {
temp = new File(path + File.separator + tempList[i]);
}
if (temp.isFile()) {
temp.delete();
}
if (temp.isDirectory()) {
delAllFile(path+"/"+ tempList[i]);//先删除文件夹里面的文件
delFolder(path+"/"+ tempList[i]);//再删除空文件夹
}
}
}
/**
* 复制单个文件
* @param oldPath String 原文件路径 如：c:/fqf.txt
* @param newPath String 复制后路径 如：f:/fqf.txt
* @return boolean
*/
public void copyFile(String oldPath, String newPath) {
try {
System.out.println("************************oldpath="+oldPath);
System.out.println("************************newpath="+newPath);
int bytesum = 0;
int byteread = 0;
File oldfile = new File(oldPath);
if (oldfile.exists()) { //文件存在时
InputStream inStream = new FileInputStream(oldPath); //读入原文件
FileOutputStream fs = new FileOutputStream(newPath);
byte[] buffer = new byte[1444];
int length;
while ( (byteread = inStream.read(buffer)) != -1) {
bytesum += byteread; //字节数 文件大小
System.out.println(bytesum);
fs.write(buffer, 0, byteread);
}
inStream.close();
}
}
catch (Exception e) {
System.out.println("复制单个文件操作出错");
e.printStackTrace();
}
}
/**
* 复制整个文件夹内容
* @param oldPath String 原文件路径 如：c:/fqf
* @param newPath String 复制后路径 如：f:/fqf/ff
* @return boolean
*/
public void copyFolder(String oldPath, String newPath) {
try {
(new File(newPath)).mkdirs(); //如果文件夹不存在 则建立新文件夹
File a=new File(oldPath);
String[] file=a.list();
File temp=null;
for (int i = 0; i < file.length; i++) {
if(oldPath.endsWith(File.separator)){
temp=new File(oldPath+file[i]);
}
else{
temp=new File(oldPath+File.separator+file[i]);
}
if(temp.isFile()){
FileInputStream input = new FileInputStream(temp);
FileOutputStream output = new FileOutputStream(newPath + "/" +
(temp.getName()).toString());
byte[] b = new byte[1024 * 5];
int len;
while ( (len = input.read(b)) != -1) {
output.write(b, 0, len);
}
output.flush();
output.close();
input.close();
}
if(temp.isDirectory()){//如果是子文件夹
copyFolder(oldPath+"/"+file[i],newPath+"/"+file[i]);
}
}
}
catch (Exception e) {
System.out.println("复制整个文件夹内容操作出错");
e.printStackTrace();
}
}
/**
* 移动文件到指定目录
* @param oldPath String 如：c:/fqf.txt
* @param newPath String 如：d:/fqf.txt
*/
public void moveFile(String oldPath, String newPath) {
copyFile(oldPath, newPath);
delFile(oldPath);
}
/**
* 移动文件到指定目录
* @param oldPath String 如：c:/fqf.txt
* @param newPath String 如：d:/fqf.txt
*/
public void moveFolder(String oldPath, String newPath) {
copyFolder(oldPath, newPath);
delFolder(oldPath);
}
}

2、利用jxl.jar包操作excel
jxl.jar好象网上很难找到下载，如果有需要的可以发短消息给我。关于jxl的资料不难找到，这里只说我用到的。
根据模板文件 m1.xls(普通的没输入值的excel) 建立新的excel文件。

jxl.Workbook wbook1 = jxl.Workbook.getWorkbook(new File("c:/m1.xls"));
//建立只读的wbook1,m1.xls必须以存在
WritableWorkbook copy = Workbook.createWorkbook(new File("d:/new.xls"), wbook1);
//建立可写的copy, new.xls 为通过wbook1 建立的
WritableSheet sheet1 = copy.getSheet(0);
//建立可写的sheet1, 为索引的第一个 getSheet(0),也就是excel里的第一张表
WritableCell cell;
jxl.write.Label l;
cell = sheet1.getWritableCell(0,0);
l = (jxl.write.Label) cell;
//建立可写的某一格,getWritableCell(0,0) 这里的参数0,0分别代表 列,行
l.setString("aaa");
//修改其值为 aaa
copy.write();
wbook1.close();
copy.close();
//保存并关闭excel表,释放资源

3、打包为zip文件
网上有这种资料，甚至有写好的类，不过我经过一点修改，才能正常使用。类文件如下：
import java.io.File;
import org.apache.tools.zip.ZipOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
public class CompressBook {
public CompressBook() {
}
public void zip(String inputFileName,String zipFileName) throws Exception {
System.out.println(zipFileName);
zip(zipFileName, new File(inputFileName));

}
private void zip(String zipFileName, File inputFile) throws Exception {
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipFileName));
zip(out, inputFile, "");
System.out.println("zip done");
out.close();
}
private void zip(ZipOutputStream out, File f, String base) throws Exception {
if (f.isDirectory()) {
File[] fl = f.listFiles();
out.putNextEntry(new org.apache.tools.zip.ZipEntry(base + "/"));
base = base.length() == 0 ? "" : base + "/";
for (int i = 0; i < fl.length; i++) {
zip(out, fl[i], base + fl[i].getName());
}
}
else {
out.putNextEntry(new org.apache.tools.zip.ZipEntry(base));
FileInputStream in = new FileInputStream(f);
int b;
System.out.println(base);
while ( (b = in.read()) != -1) {
out.write(b);
}
in.close();
}
}
}

import java.io.File;
import org.apache.tools.zip.ZipOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
public class CompressBook {
public CompressBook() {
}
public void zip(String inputFileName,String zipFileName) throws Exception {
System.out.println(zipFileName);
zip(zipFileName, new File(inputFileName));

}
private void zip(String zipFileName, File inputFile) throws Exception {
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipFileName));
zip(out, inputFile, "");
System.out.println("zip done");
out.close();
}
private void zip(ZipOutputStream out, File f, String base) throws Exception {
if (f.isDirectory()) {
File[] fl = f.listFiles();
out.putNextEntry(new org.apache.tools.zip.ZipEntry(base + "/"));
base = base.length() == 0 ? "" : base + "/";
for (int i = 0; i < fl.length; i++) {
zip(out, fl[i], base + fl[i].getName());
}
}
else {
out.putNextEntry(new org.apache.tools.zip.ZipEntry(base));
FileInputStream in = new FileInputStream(f);
int b;
System.out.println(base);
while ( (b = in.read()) != -1) {
out.write(b);
}
in.close();
}
}
}

4、正则表达式要实现个功能，类似ubb
输入页面输入<@31|测试@> 的信息，处理的时候，将31作为连接的参数
<a href=xx.jsp?id=31>测试</a>
import java.util.regex.*;
String content=transFormat.GBToUnicode(request.getParameter("content"));
//得到 输入的内容,这里的transFormat，是自定义的，用于处理中文字符乱码的问题。
Pattern p=null; //正则表达式
Matcher m=null; //操作的字符串
String s;
p = Pattern.compile("(<@)([//w]*)([//|])([^@>]*)(@>)");
m = p.matcher(content);
s=m.replaceAll("<a href=tudi_xm.jsp?id=$2 target=_blank>$4</a>");