Delete entry from HashMap

This question already has an answer here: Iterate through a HashMap [duplicate] 7 answers 迭代你的地图Iterator it = adjMap.entrySet().iterator(); while (it.hasNext()) { Entry item = it.next(); map.remove(item.getKey()); } I think for-each loops are not allowed to alter the iterated object. To remove entries you should use an iterator. Compare to map-Iteration for

从HashMap中删除条目

这个问题在这里已经有了答案: 迭代通过HashMap [复制] 7个答案 迭代你的地图Iterator it = adjMap.entrySet().iterator(); while (it.hasNext()) { Entry item = it.next(); map.remove(item.getKey()); } 我认为,每个循环都不允许改变迭代的对象。 要删除条目,你应该使用迭代器。 比较map-Iteration的例子。 您可以改为使用ConcurrentHashMap ,或者创建HashMap的副本并对副本进行任何更改

Write LinkedHashMap to a text file?

This question already has an answer here: How to efficiently iterate over each entry in a 'Map'? 38 answers Iterate through a HashMap [duplicate] 7 answers Because you're trying to write your entire Map to the file and not individual entries you could use writeObject() and readObject() like this: Map<String, String> m1 = new LinkedHashMap<String, String>(16, 0.75f,

将LinkedHashMap写入文本文件?

这个问题在这里已经有了答案: 如何有效地迭代'Map'中的每个条目? 38个答案 迭代通过HashMap [复制] 7个答案 因为你正试图将整个Map写入文件而不是单个条目,所以你可以像这样使用writeObject()和readObject() : Map<String, String> m1 = new LinkedHashMap<String, String>(16, 0.75f, true); m1.put("John Smith", "555-555-5555"); m1.put("Jane Smith", "444-444-4444"); //Write to file F

best way to call a method of each object in a collection

This question already has an answer here: Iterate through a HashMap [duplicate] 7 answers for (MyOb o: objs.values()) { o.tick(); } 您也可以使用Java 8中的流API执行此操作: objs.values().forEach(v -> v.tick()); objs.forEach((k, v) -> v.tick());

调用集合中每个对象的方法的最佳方法

这个问题在这里已经有了答案: 迭代通过HashMap [复制] 7个答案 for (MyOb o: objs.values()) { o.tick(); } 您也可以使用Java 8中的流API执行此操作: objs.values().forEach(v -> v.tick()); objs.forEach((k, v) -> v.tick());

Finding the n largest values in a hashmap

This question already has an answer here: Iterate through a HashMap [duplicate] 7 answers Probably this is not the most efficient way to do, but it should solve your problem: static HashMap<String, Integer> nLargest(HashMap<String, Integer> map, int n) { //map and n largest values to search for Integer value; ArrayList<String> keys = new ArrayList<>(n); //to

在hashmap中查找n个最大值

这个问题在这里已经有了答案: 迭代通过HashMap [复制] 7个答案 可能这不是最有效的方法,但它应该解决您的问题: static HashMap<String, Integer> nLargest(HashMap<String, Integer> map, int n) { //map and n largest values to search for Integer value; ArrayList<String> keys = new ArrayList<>(n); //to store keys of the n largest values ArrayList<Integer> valu

Iterating through/Updating HashMap

This question already has an answer here: Iterate through a HashMap [duplicate] 7 answers How to efficiently iterate over each entry in a 'Map'? 38 answers 利用地图:首先浏览其他收藏并进行操作。 for(String blacklisted : blacklist) { wordcounts.remove(blacklisted); } for(String mapping : mappings) { String oldKey = // get old key String value = wordcounts.get(oldKey);

迭代/更新HashMap

这个问题在这里已经有了答案: 迭代通过HashMap [复制] 7个答案 如何有效地迭代'Map'中的每个条目? 38个答案 利用地图:首先浏览其他收藏并进行操作。 for(String blacklisted : blacklist) { wordcounts.remove(blacklisted); } for(String mapping : mappings) { String oldKey = // get old key String value = wordcounts.get(oldKey); wordcounts.remove(oldKey); wordcounts.put(map

java.util.HashSet int iteration order

This question already has an answer here: Iterate through a HashMap [duplicate] 7 answers Docs says This class implements the Set interface, backed by a hash table (actually a HashMap instance). It makes no guarantees as to the iteration order of the set; in particular, it does not guarantee that the order will remain constant over time. This class permits the null element. go for Link

java.util.HashSet int迭代次序

这个问题在这里已经有了答案: 迭代通过HashMap [复制] 7个答案 Docs说 这个类实现了Set接口,由一个哈希表(实际上是一个HashMap实例)支持。 它对集合的迭代次序没有任何保证; 特别是,它不能保证订单会随着时间的推移保持不变。 这个类允许null元素。 去LinkedHashSet HashSet不维护广告订单。 你需要的是一个LinkedHashSet 。 HashSet类不保证您输入数据的顺序。 如果你不把你的List放在HashSet ,而是继

Update Eclipse with Android development tools v. 23

I updated Eclipse with the new SDK tools (rev. 23), but now when Eclipse starts I receive the error: This Android SDK requires Android Developer Toolkit version 23.0.0 or above. Current version is 22.6.3.v201404151837-1123206. Please update ADT to the latest version. No updates were found with "Check for updates" . If I try "Install new software" , I can see version 23,

使用Android开发工具v。23更新Eclipse

我使用新的SDK工具更新了Eclipse(修订版23),但现在Eclipse启动时收到错误消息: 此Android SDK需要Android Developer Toolkit版本23.0.0或更高版本。 当前版本是22.6.3.v201404151837-1123206。 请更新ADT到最新版本。 “检查更新”未找到更新 。 如果我尝试“安装新软件” ,我可以看到版本23,但由于以下错误我无法升级: Cannot complete the install because of a conflicting dependency. Software being installed:

source 1.7 in Android Studio and Gradle

I'm getting following error when trying to compile my project in Android Studio: Gradle: error: diamond operator is not supported in -source 1.6 I have 1.7 set as target in all project preferences I've found. Also the path displayed in project SDK's under 1.7 SDK is correct path to java 1.7 installation. Even when I run java -version in terminal, it tells me I'm running on ja

Android Studio和Gradle中的源代码1.7

尝试在Android Studio中编译我的项目时出现以下错误: Gradle: error: diamond operator is not supported in -source 1.6 在所有我找到的项目偏好中,我有1.7个目标。 此外,项目SDK的1.7 SDK下显示的路径是正确的Java 1.7安装路径。 即使我在终端中运行java -version,它也会告诉我我正在运行java 1.7。 我曾尝试将JAVA_HOME env变量设置为: /Library/Java/JavaVirtualMachines/jdk1.7.0_25.jdk/Contents/Home 错误

Can the Android SDK work with JDK 1.7?

I just installed the Android SDK R16 and JDK 7, but I keep getting the error Android requires compiler compliance level 5.0 or 6.0. Found '1.7' instead. Please use Android Tools > Fix Project Properties." I am using some features of the JRE 1.7, so I can't just switch it to 1.6. How can I fix this problem? You just need 1.6 present on your PC. I had the same problem.

Android SDK可以使用JDK 1.7吗?

我刚刚安装了Android SDK R16和JDK 7,但我一直在收到错误 Android需要编译器符合性级别5.0或6.0。 取而代之的是“1.7”。 请使用Android工具>修复项目属性。“ 我正在使用JRE 1.7的一些功能,所以我不能将它切换到1.6。 我该如何解决这个问题? 你只需要在你的PC上存在1.6。 我有同样的问题。 安装1.6 JDK,并将其作为已知的JDK添加,但实际上并没有为您的项目选择它。 是的,您可以使用Java 1.7进行Android开发。

diamond operator is not supported

This question already has an answer here: How to set -source 1.7 in Android Studio and Gradle 8 answers Android needs java source compliance 5.0 or 6.0 (Java5/6). Java7 is not supported out of the box. The're articles describing hacks on how to use some of java7 features: http://www.informit.com/articles/article.aspx?p=1966024. Also see Java 7 language features with Android, Does Andr

钻石操作员不受支持

这个问题在这里已经有了答案: 如何在Android Studio和Gradle 8中设置-source 1.7答案 Android需要Java源代码5.0或6.0(Java5 / 6)。 不支持Java7的开箱即用。 这篇文章描述了如何使用java7的一些特性:http://www.informit.com/articles/article.aspx?p=1966024。 另请参阅Android的Java 7语言功能,Android计划是否支持Java7?,Android SDK可以使用JDK 1.7吗? 现在允许API 19 KitKat钻石。 以下是为Android Stud