将String数组转换成ArrayList

package org.donkey.app.ListToArrayList;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

/**

* Created with IntelliJ IDEA.

* User: Donkey

* Date: 13-11-24

* Time: 上午10:44

* 用于将String类型的数组转变为ArrayList

*/

public class StringArrayToArrayListTest {

public static void main(String[] args){

StringArrayToArrayListTest.test1();

StringArrayToArrayListTest.test2();

StringArrayToArrayListTest.test3();

}

public static void test1(){

String[] words = {"ace", "boom", "crew", "dog", "eon"};

List<String> wordList = Arrays.asList(words);

//wordList.add("1");

for (String e : wordList){

System.out.println(e);

}

}

public static void test2(){

String[] words = {"ace", "boom", "crew", "dog", "eon"};

List<String> wordList = new ArrayList<String>(Arrays.asList(words));

wordList.add("1");

for (String e : wordList){

System.out.println(e);

}

}

public static void test3(){

String[] words = {"ace", "boom", "crew", "dog", "eon"};

List<String> wordList = new ArrayList<String>(words.length);

for (String e : words){

wordList.add(e);

}

wordList.add("2");

for (String e : wordList){

System.out.println(e);

}

}

}

将三种方式的算法对比一下，我们可以分析出test1中的方法是效率最高的，因为他不需要复制array中的内容，而是直接返回一个List,但这种方式是不能添加和删除元素的。

test2和test3本质上是一种方式，它们将创建array的副本到ArrayList中，当然就可以实现增删功能。

两种方式要根据自己的需求而定。

PS:使用方法一的时候出现了下面的错误，最后使用方法二没有问题

03-09 12:54:42.699: E/AndroidRuntime(21587): FATAL EXCEPTION: AsyncTask #1

03-09 12:54:42.699: E/AndroidRuntime(21587): Process: com.clockrock.freeshare, PID: 21587

03-09 12:54:42.699: E/AndroidRuntime(21587): java.lang.RuntimeException: An error occured while executing doInBackground()

03-09 12:54:42.699: E/AndroidRuntime(21587): at android.os.AsyncTask$3.done(AsyncTask.java:300)

03-09 12:54:42.699: E/AndroidRuntime(21587): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)

03-09 12:54:42.699: E/AndroidRuntime(21587): at java.util.concurrent.FutureTask.setException(FutureTask.java:222)

03-09 12:54:42.699: E/AndroidRuntime(21587): at java.util.concurrent.FutureTask.run(FutureTask.java:242)

03-09 12:54:42.699: E/AndroidRuntime(21587): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)

03-09 12:54:42.699: E/AndroidRuntime(21587): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)

03-09 12:54:42.699: E/AndroidRuntime(21587): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)

03-09 12:54:42.699: E/AndroidRuntime(21587): at java.lang.Thread.run(Thread.java:848)

03-09 12:54:42.699: E/AndroidRuntime(21587): Caused by: java.lang.ClassCastException: java.util.Arrays$ArrayList cannot be cast to java.util.ArrayList

03-09 12:54:42.699: E/AndroidRuntime(21587): at com.clockrock.pla.activity.PlaImageFragment$ContentTask.parseNewsJSON(PlaImageFragment.java:113)

03-09 12:54:42.699: E/AndroidRuntime(21587): at com.clockrock.pla.activity.PlaImageFragment$ContentTask.doInBackground(PlaImageFragment.java:60)

03-09 12:54:42.699: E/AndroidRuntime(21587): at com.clockrock.pla.activity.PlaImageFragment$ContentTask.doInBackground(PlaImageFragment.java:1)

03-09 12:54:42.699: E/AndroidRuntime(21587): at android.os.AsyncTask$2.call(AsyncTask.java:288)

03-09 12:54:42.699: E/AndroidRuntime(21587): at java.util.concurrent.FutureTask.run(FutureTask.java:237)

03-09 12:54:42.699: E/AndroidRuntime(21587): ... 4 more