命令:javac -Xlint:unckecked TextFile.java
编译结果:TextFile.java:34:警告: [unchecked]对作为普通类型java.util.ArrayList的成员的ArrayList(java.util.Collection<? extends E>)的调用未经检查
super(Arrays.asList(read(fileName).split("\n")));
以下是源码:
//: com:bruceeckel:util:TextFile.java
// Static functions for reading and writing text files as
// a single string, and treating a file as an ArrayList.
// {Clean: test.txt test2.txt}
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
package com.bruceeckel.util;
import java.io.*;
import java.util.*;
public class TextFile extends ArrayList {
// Tools to read and write files as single strings:
public static String
read(String fileName) throws IOException {
StringBuffer sb = new StringBuffer();
BufferedReader in =
new BufferedReader(new FileReader(fileName));
String s;
while((s = in.readLine()) != null) {
sb.append(s);
sb.append("\n");
}
in.close();
return sb.toString();
}
public static void
write(String fileName, String text) throws IOException {
PrintWriter out = new PrintWriter(
new BufferedWriter(new FileWriter(fileName)));
out.print(text);
out.close();
}
public TextFile(String fileName) throws IOException {
super(Arrays.asList(read(fileName).split("\n")));
}
public void write(String fileName) throws IOException {
PrintWriter out = new PrintWriter(
new BufferedWriter(new FileWriter(fileName)));
for(int i = 0; i < size(); i++)
out.println(get(i));
out.close();
}
// Simple test:
public static void main(String[] args) throws Exception {
String file = read("TextFile.java");
write("test.txt", file);
TextFile text = new TextFile("test.txt");
text.write("test2.txt");
}
} ///:~
------解决方案--------------------
你想问什么？看过Java 1.5里面关于Generics的东西吗？
------解决方案--------------------
我的《THINK IN JAVA》里的光盘是C++的
------解决方案--------------------
用到泛型
JDK 5新增
你的版本应该是JDK5或者以上