=======先参见以下源代码=========

package example.file;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileReader;

import java.io.FileWriter;

public class OrderFile {

private static File file;

private static FileWriter writer;

private static BufferedReader reader;

static {

file = new File("D:\\OrderFile.txt");

}

public static File getFile() {

return file;

}

public static void setFile(File file) {

OrderFile.file = file;

}

public static FileWriter getWriter() {

return writer;

}

public static void setWriter(FileWriter writer) {

OrderFile.writer = writer;

}

@SuppressWarnings("unused")

private synchronized static void saveOrder(String text) throws Exception {

if (null == writer){

writer = new FileWriter(file, true);

}

writer.write(text + "\r\n");

writer.flush();

}

@SuppressWarnings("unused")

private static String readOrder() throws Exception {

if (null == reader){

reader = new BufferedReader(new FileReader(file));

}

StringBuffer buffer = new StringBuffer();

String line = reader.readLine();

while (null != line){

buffer.append(line);

buffer.append("\r\n");

line = reader.readLine();

}

closeFileReader();

return buffer.toString();

}

@SuppressWarnings("unused")

private static void closeFileWriter() throws Exception {

if (null != writer){

writer.close();

}

}

@SuppressWarnings("unused")

private static void closeFileReader() throws Exception {

if (null != reader){

reader.close();

}

}

@SuppressWarnings("unused")

private static String buffer(String retCode){

StringBuffer buffer = new StringBuffer();

buffer.append("");

buffer.append(""+retCode+"");

buffer.append("追加文件");

buffer.append("");

return buffer.toString();

}

public static void main(String[] args) throws Exception {

Long t1 = 0L, t2 = 0L;

t1 = System.currentTimeMillis();

for (int i = 1; i <= 100; i++){

OrderFile.saveOrder(buffer(String.valueOf(i)));

}

t2 = System.currentTimeMillis() - t1;

System.out.println("写入所需时间:" + t2);

System.out.println("文件大小:" + OrderFile.getFile().length());

OrderFile.closeFileWriter();

t1 = System.currentTimeMillis();

System.out.println(OrderFile.readOrder());

t2 = System.currentTimeMillis() - t1;

System.out.println("读取所需时间:" + t2);

}

}

使用FileWriter时,利用FileWriter(Filefile, boolean append) 构造一个FileWriter对象,当append参数值为true时, 会将字节写入文件的末尾,而不是文件的开头.

分享到：

2010-06-12 09:50

浏览 5334

评论