增加目录

Author: mahongliang

contents/create-arraylist-arraylistt-from-array-t.md

@@ -5,16 +5,24 @@
 ```java
 Element[] array = {new Element(1),new Element(2),new Element(3)};
 ```
-如何将其转换为ArrayList`<Element>` arraylist呢？
+如何将其转换为ArrayList`<Element>` arraylist = ？？？
+
+### 回答1 ###
+
+    `new ArrayList<Element>(Arrays.asList(array))`
+
+###回答2
 
-###回答
 Arrays.asList(array)或者Arrays.asList(new Element(1),new Element(2),new Element(3))
 
 不过，这样做有些坑要注意：
 
 1. 这样做生成的list，是定长的。也就是说，如果你对它做add或者remove，都会抛UnsupportedOperationException。
 2. 如果修改数组的值，list中的对应值也会改变！
 
+**Arrays.asList() 返回的是Arrays内部静态类，而不是Java.util.ArrayList的类。这个java.util.Arrays.ArrayList有set(),get(),contains()方法，但是没有任何add() 方法，所以它是固定大小的**
+
+
 如果希望避免这两个坑，请改用这个方式
 ```java
 Collections.addAll(arraylist, array);

contents/目录.md

@@ -0,0 +1,202 @@
+# [目录](http://stackoverflow.com/questions/tagged/java?page=1&sort=votes&pagesize=15) #
+
+## [1、为什么处理排序过得数组比没有排序的数组快](http://stackoverflow.com/questions/11227809/why-is-processing-a-sorted-array-faster-than-an-unsorted-array "Why is processing a sorted array faster than an unsorted array?") ##
+
+
+## [2、为什么在1927年的两个时间相减会产生奇怪的结果](http://stackoverflow.com/questions/6841333/why-is-subtracting-these-two-times-in-1927-giving-a-strange-result) ##
+
+## [3、Java是传引用还是传值](http://stackoverflow.com/questions/40480/is-java-pass-by-reference-or-pass-by-value) ##
+
+## [4、Java += 操作符](http://stackoverflow.com/questions/8710619/java-operator) ##
+
+## [5、避免！=null 声明](http://stackoverflow.com/questions/271526/avoiding-null-statements) ##
+
+## [6、Android适当的用例UserManager.isUserAGoat()](http://stackoverflow.com/questions/13375357/proper-use-cases-for-android-usermanager-isuseragoat) ##
+
+## [7、HashMap和HaspTable的区别](http://stackoverflow.com/questions/40471/differences-between-hashmap-and-hashtable) ##
+
+## [8、InputStream转换为String](http://stackoverflow.com/questions/309424/read-convert-an-inputstream-to-a-string) ##
+
+## [9、为什么在存密码时char[]要优于String](http://stackoverflow.com/questions/8881291/why-is-char-preferred-over-string-for-passwords-in-java) ##
+
+## [10、遍历HashMap](http://stackoverflow.com/questions/1066589/iterate-through-a-hashmap) ##
+
+## [11、用数组创建一个ArrayList](http://stackoverflow.com/questions/157944/create-arraylist-from-array) ##
+
+## [12、产生特定范围的随机数](http://stackoverflow.com/questions/363681/generating-random-integers-in-a-specific-range) ##
+
+## [13、创建内存泄露？](http://stackoverflow.com/questions/6470651/creating-a-memory-leak-with-java) ##
+
+## [14、LinkedList和ArrayList区别](http://stackoverflow.com/questions/322715/when-to-use-linkedlist-over-arraylist) ##
+
+## [15、为什么动态的答应B比答应#慢](http://stackoverflow.com/questions/21947452/why-is-printing-b-dramatically-slower-than-printing) ##
+
+## [16、serialVersionUID是什么](http://stackoverflow.com/questions/285793/what-is-a-serialversionuid-and-why-should-i-use-it) ##
+
+## [17、把字符串转换为Int](http://stackoverflow.com/questions/5585779/converting-string-to-int-in-java) ##
+
+## [18、public、default、protected、private的区别](http://stackoverflow.com/questions/215497/difference-between-public-default-protected-and-private) ##
+
+## [19、Android设备是否有唯一的ID](http://stackoverflow.com/questions/2785485/is-there-a-unique-android-device-id) ##
+
+## [20、怎么样测试私有方法，字段和内部类](http://stackoverflow.com/questions/34571/how-to-test-a-class-that-has-private-methods-fields-or-inner-classes) ##
+
+## [21、怎样有效的遍历Map中的entry](http://stackoverflow.com/questions/46898/how-to-efficiently-iterate-over-each-entry-in-a-map) ##
+
+## [22、使用java.net.URLConnection处理HTTP requests](http://stackoverflow.com/questions/2793150/using-java-net-urlconnection-to-fire-and-handle-http-requests) ##
+
+## [23、为什么这段代码使用随机字符串答应"hello world"](http://stackoverflow.com/questions/15182496/why-does-this-code-using-random-strings-print-hello-world) ##
+
+## [24、 如果使用Maven创建外部JAR](http://stackoverflow.com/questions/574594/how-can-i-create-an-executable-jar-with-dependencies-using-maven) ##
+
+## [25、怎样判断数组包含一个特定的值](http://stackoverflow.com/questions/1128723/how-can-i-test-if-an-array-contains-a-certain-value) ##
+
+## [26、如何在JSP中避免java代码](http://stackoverflow.com/questions/3177733/how-to-avoid-java-code-in-jsp-files) ##
+
+## [27、一行代码初始化ArrayList](http://stackoverflow.com/questions/1005073/initialization-of-an-arraylist-in-one-line) ##
+
+## [28、finally在java一定会被执行吗](http://stackoverflow.com/questions/65035/does-finally-always-execute-in-java) ##
+
+## [29、"implements Runnable"和"extends Thread"](http://stackoverflow.com/questions/541487/implements-runnable-vs-extends-thread) ##
+
+## [30、如何在一个构造函数中调用另一个](http://stackoverflow.com/questions/285177/how-do-i-call-one-constructor-from-another-in-java) ##
+
+## [31、String转换为Enum](http://stackoverflow.com/questions/604424/convert-a-string-to-an-enum-in-java) ##
+
+## [32、在//后代码会被执行](http://stackoverflow.com/questions/30727515/why-is-executing-java-code-in-comments-with-certain-unicode-characters-allowed) ##
+
+## [33、处理java.lang.OutOfMemoryError:PermGen space错误](http://stackoverflow.com/questions/88235/dealing-with-java-lang-outofmemoryerror-permgen-space-error) ##
+
+## [34、退出嵌套循环](http://stackoverflow.com/questions/886955/breaking-out-of-nested-loops-in-java) ##
+
+## [35、Android SDK 安装后找不到JDK](http://stackoverflow.com/questions/4382178/android-sdk-installation-doesnt-find-jdk) ##
+
+## [36、Java内部类和嵌套类](http://stackoverflow.com/questions/70324/java-inner-class-and-static-nested-class) ##
+
+## [37、在导入项目后出现必须覆盖超类方法的错误](http://stackoverflow.com/questions/1678122/must-override-a-superclass-method-errors-after-importing-a-project-into-eclips) ##
+
+## [38、错误Unsupported major.minor version 51.0 error](http://stackoverflow.com/questions/10382929/how-to-fix-unsupported-major-minor-version-51-0-error) ##
+
+## [39、声明数组](http://stackoverflow.com/questions/1200621/declare-array-java) ##
+
+## [40、反射的作用](http://stackoverflow.com/questions/37628/what-is-reflection-and-why-is-it-useful) ##
+
+## [41、Map值排序](http://stackoverflow.com/questions/109383/sort-a-mapkey-value-by-values-java) ##
+
+## [42、产生字母数字型随机数](http://stackoverflow.com/questions/41107/how-to-generate-a-random-alpha-numeric-string) ##
+
+## [43、判断一个数的根号是整数](http://stackoverflow.com/questions/295579/fastest-way-to-determine-if-an-integers-square-root-is-an-integer) ##
+
+## [44、用==或者equals()比较enum成员](http://stackoverflow.com/questions/1750435/comparing-java-enum-members-or-equals) ##
+
+## [45、最简单的答应数组](http://stackoverflow.com/questions/409784/whats-the-simplest-way-to-print-a-java-array) ##
+
+## [46、java是否支持默认参数值](http://stackoverflow.com/questions/997482/does-java-support-default-parameter-values) ##
+
+## [47、接口和抽象类区别](http://stackoverflow.com/questions/1913098/what-is-the-difference-between-an-interface-and-abstract-class) ##
+
+## [48、IntelliJ持久化行号](http://stackoverflow.com/questions/13751/how-can-i-permanently-have-line-numbers-in-intellij) ##
+
+## [49、StringBuilder and StringBuffer](http://stackoverflow.com/questions/355089/stringbuilder-and-stringbuffer) ##
+
+## [50、怎么连接两个数组](http://stackoverflow.com/questions/80476/how-can-i-concatenate-two-arrays-in-java) ##
+
+## [51、在JUit中怎么断言异常](http://stackoverflow.com/questions/156503/how-do-you-assert-that-a-certain-exception-is-thrown-in-junit-4-tests) ##
+
+## [52、字符串比较](http://stackoverflow.com/questions/513832/how-do-i-compare-strings-in-java) ##
+
+## [53、根据文件的内容创建字符串](http://stackoverflow.com/questions/326390/how-to-create-a-java-string-from-the-contents-of-a-file) ##
+
+## [54、Failed to load the JNI shared Library (JDK)](http://stackoverflow.com/questions/7352493/failed-to-load-the-jni-shared-library-jdk) ##
+
+## [55、JavaBean](http://stackoverflow.com/questions/3295496/what-is-a-javabean-exactly) ##
+
+## [56、为什么我不能打开一个字符串](http://stackoverflow.com/questions/338206/why-cant-i-switch-on-a-string) ##
+
+## [57、stack trace转换String](http://stackoverflow.com/questions/1149703/how-can-i-convert-a-stack-trace-to-a-string) ##
+
+## [58、java核心代码的Gof设计模式例子](http://stackoverflow.com/questions/1673841/examples-of-gof-design-patterns-in-javas-core-libraries) ##
+
+## [59、Apache Camel](http://stackoverflow.com/questions/8845186/what-exactly-is-apache-camel) ##
+
+## [60、java为什么会有临时变量](http://stackoverflow.com/questions/910374/why-does-java-have-transient-variables) ##
+
+## [61、Servlet 怎么工作](http://stackoverflow.com/questions/3106452/how-do-servlets-work-instantiation-shared-variables-and-multithreading) ##
+
+## [62、重写equals和hashCode](http://stackoverflow.com/questions/27581/what-issues-should-be-considered-when-overriding-equals-and-hashcode-in-java) ##
+
+## [63、得到当前stack trace](http://stackoverflow.com/questions/1069066/get-current-stack-trace-in-java) ##
+
+## [64、foreach工作原理](http://stackoverflow.com/questions/85190/how-does-the-java-for-each-loop-work) ##
+
+## [65、Access restriction on class due to restriction on required library rt.jar?](http://stackoverflow.com/questions/860187/access-restriction-on-class-due-to-restriction-on-required-library-rt-jar) ##
+
+## [66、wait()和sleep()区别](http://stackoverflow.com/questions/1036754/difference-between-wait-and-sleep) ##
+
+## [67、产生MD5hash](http://stackoverflow.com/questions/415953/how-can-i-generate-an-md5-hash) ##
+
+## [68、在调用instanceof之前是否要检测is null](http://stackoverflow.com/questions/2950319/is-null-check-needed-before-calling-instanceof) ##
+
+## [69、Download a file with Android, and showing the progress in a ProgressDialog](http://stackoverflow.com/questions/3028306/download-a-file-with-android-and-showing-the-progress-in-a-progressdialog) ##
+
+## [70、初始化静态Map](http://stackoverflow.com/questions/507602/how-can-i-initialize-a-static-map) ##
+
+## [71、怎么发现Android应用的内存只用量](http://stackoverflow.com/questions/2298208/how-do-i-discover-memory-usage-of-my-application-in-android) ##
+
+## [72、在遍历list的时候，remove一个值，避免出现concurrenModificationExcetiion](http://stackoverflow.com/questions/223918/iterating-through-a-list-avoiding-concurrentmodificationexception-when-removing) ##
+
+## [73、在java classpath中设置多行jars](http://stackoverflow.com/questions/219585/setting-multiple-jars-in-java-classpath) ##
+
+## [74、Hibernate hbm2ddl.auto possible values and what they do](http://stackoverflow.com/questions/438146/hibernate-hbm2ddl-auto-possible-values-and-what-they-do) ##
+
+## [75、split a String](http://stackoverflow.com/questions/3481828/how-to-split-a-string-in-java) ##
+
+## [76、LINQ for java](http://stackoverflow.com/questions/1217228/what-is-the-java-equivalent-for-linq) ##
+
+## [77、What's the difference between @Component, @Repository & @Service annotations in Spring](http://stackoverflow.com/questions/6827752/whats-the-difference-between-component-repository-service-annotations-in) ##
+
+## [78、Can I add jars to maven 2 build classpath without installing them](http://stackoverflow.com/questions/364114/can-i-add-jars-to-maven-2-build-classpath-without-installing-them) ##
+
+## [79、How to round a number to n decimal places in Java](http://stackoverflow.com/questions/153724/how-to-round-a-number-to-n-decimal-places-in-java) ##
+
+## [80、对ArrayList的对象属性排序](http://stackoverflow.com/questions/2784514/sort-arraylist-of-custom-objects-by-property) ##
+
+## [81、创建和写文件](http://stackoverflow.com/questions/2885173/how-to-create-a-file-and-write-to-a-file-in-java) ##
+
+## [82、Update Eclipse with Android development tools v. 23](http://stackoverflow.com/questions/24437564/update-eclipse-with-android-development-tools-v-23) ##
+
+## [83、Uncatchable ChuckNorrisException](http://stackoverflow.com/questions/13883166/uncatchable-chucknorrisexception) ##
+
+## [84、怎么在一个整数的左边填充0](http://stackoverflow.com/questions/473282/how-can-i-pad-an-integers-with-zeros-on-the-left) ##
+
+## [85、创建泛型数组](http://stackoverflow.com/questions/529085/how-to-create-a-generic-array-in-java) ##
+
+## [86、判断三个以上为true条件](http://stackoverflow.com/questions/3076078/check-if-at-least-two-out-of-three-booleans-are-true) ##
+
+## [87、ThreadLocal variable](http://stackoverflow.com/questions/817856/when-and-how-should-i-use-a-threadlocal-variable) ##
+
+## [88、JSF、Servlet、JSP区别](http://stackoverflow.com/questions/2095397/what-is-the-difference-between-jsf-servlet-and-jsp) ##
+
+## [89、为什么java向量类被认为是过时的和被废弃](http://stackoverflow.com/questions/1386275/why-is-java-vector-class-considered-obsolete-or-deprecated) ##
+
+## [90、反编译DEX为源码](http://stackoverflow.com/questions/1249973/decompiling-dex-into-java-sourcecode) ##
+
+## [91、ArrayList<String>转换为String[]数组](http://stackoverflow.com/questions/5374311/convert-arrayliststring-to-string-array) ##
+
+## [92、软引用和弱引用的区别](http://stackoverflow.com/questions/299659/what-is-the-difference-between-a-soft-reference-and-a-weak-reference-in-java) ##
+
+## [93、Efficiency of Java “Double Brace Initialization”](http://stackoverflow.com/questions/924285/efficiency-of-java-double-brace-initialization) ##
+
+## [94、实现单例模式的最有效方法](http://stackoverflow.com/questions/70689/what-is-an-efficient-way-to-implement-a-singleton-pattern-in-java) ##
+
+## [95、java中什么相当于C++的<L,R>](http://stackoverflow.com/questions/156275/what-is-the-equivalent-of-the-c-pairl-r-in-java) ##
+
+## [96、从纯文本文件中读](http://stackoverflow.com/questions/4716503/reading-a-plain-text-file-in-java) ##
+
+## [97、Which @NotNull Java annotation should I use](http://stackoverflow.com/questions/4963300/which-notnull-java-annotation-should-i-use) ##
+
+## [98、为什么这段代码陷入无限循环](http://stackoverflow.com/questions/3831341/why-does-this-go-into-an-infinite-loop) ##
+
+## [99、Eclipse: Set maximum line length for auto formatting](http://stackoverflow.com/questions/3697287/eclipse-set-maximum-line-length-for-auto-formatting) ##
+
+## [100、Why does Math.round(0.49999999999999994) return 1](http://stackoverflow.com/questions/9902968/why-does-math-round0-49999999999999994-return-1) ##