java-5

Java Generics: Generic type defined as return type only

由 萝らか妹 提交于 2019-12-17 03:02:27
问题 I'm looking at some GXT code for GWT and I ran across this use of Generics that I can't find another example of in the Java tutorials. The class name is com.extjs.gxt.ui.client.data.BaseModelData if you want to look at all of the code. Here are the important parts: private RpcMap map; public <X> X get(String property) { if (allowNestedValues && NestedModelUtil.isNestedProperty(property)) { return (X)NestedModelUtil.getNestedValue(this, property); } return map == null ? null : (X) map.get

Porting Arrays.copyOfRange from Java 6 to Java 5

由 被刻印的时光 ゝ 提交于 2019-12-13 02:56:24
问题 I have some source code that I need to make runnable under Java 5. Unfortunetly that code uses Arrays.copyOfRange function which was only introduced in Java 6. What would be the most effective way to implement same utility using only Java 5 API? 回答1: Check out the OpenJDK 6 page - it's open source Java. You can download and read the source code yourself, find out how it's implemented, and add the functionality to the app manually. 回答2: Here goes the code from OpenJDK for those who are

What is the easiest way to iterate over all the key/value pairs of a java.util.Map in Java 5 and higher?

由 吃可爱长大的小学妹 提交于 2019-12-12 07:42:06
问题 What is the easiest way to iterate over all the key/value pairs of a java.util.Map in Java 5 and higher? 回答1: Assuming K is your key type and V is your value type: for (Map.Entry<K,V> entry : map.entrySet()) { K key = entry.getKey(); V value = entry.getValue(); // do stuff } 来源： https://stackoverflow.com/questions/585654/what-is-the-easiest-way-to-iterate-over-all-the-key-value-pairs-of-a-java-util-m

How to run a Java program using ProcessBuilder inside the other Java program. (with -cp and -Xbootclasspath commands)

由 ￣綄美尐妖づ 提交于 2019-12-10 23:56:39
问题 Here is my code. public class Test { public static void main(String[] args) { String directory = System.getProperty("user.home") + File.separator + "cache"; System.out.println(directory); // "/Users/byron1st/cache" try{ ProcessBuilder builder = new ProcessBuilder("java", "-cp", directory, "-Xbootclasspath/p:", directory, "framework.PFSystemMain"); builder.redirectErrorStream(true); builder.redirectOutput(new File(System.getProperty("user.home") + "/output.txt")); builder.start(); } catch

Spring @Cacheable not working - what's wrong with my config?

由 五迷三道 提交于 2019-12-10 18:04:40
问题 I've seen many incarnations of this same issue but I think I've tried all the fixes - my usage is quite straightforward. I had been using Ehcache which also didn't work. So, to rule out Ehcache issues and help point to something more fundamental, I moved to SimpleCacheManager and ConcurrentMapCacheFactoryBean. Here's my config: <cache:annotation-driven/> <bean id="cacheManager" class="org.springframework.cache.support.SimpleCacheManager"> <property name="caches"> <set> <bean class="org

Java: easiest way to package both Java 1.5 and 1.6 code

由 [亡魂溺海] 提交于 2019-12-10 03:28:36
问题 I want to package a piece of code that absolutely must run on Java 1.5. There's one part of the code where the program can be "enhanced" if the VM is an 1.6 VM. Basically it's this method: private long[] findDeadlockedThreads() { // JDK 1.5 only supports the findMonitorDeadlockedThreads() // method, so you need to comment out the following three lines if (mbean.isSynchronizerUsageSupported()) return mbean.findDeadlockedThreads(); else return mbean.findMonitorDeadlockedThreads(); } What would

How to iterate through a list of objects and assign children?

由 我的梦境 提交于 2019-12-08 08:56:03
问题 I have a Location POJO that stores Location objects parsed in from a JSON file, which I want to map to a graph. Each node's location in the graph corresponds to it's id field, where id="1" is the start node and id="10" is the goal node. To solve this I adapted a Node class to include methods such as setWeight() , addChildLocation() etc , But I'm not sure how to create the graph from my list of locations. I know how to create the graph by hard coding the location's and calling addChildren, by

Java 1.5 JOptionPane paint bug when using panel message/workaround?

由 纵然是瞬间 提交于 2019-12-07 09:26:30
问题 I have a JOptionPane with a custom message panel in it, in an application targeted for Java 1.5. The panel contains, among other things, a JTextField. Every 20 invocations or so, nothing in the dialog gets painted (not even the OK/Cancel buttons). If I drag the dialog off the screen and back again to force a repaint, the components are visible as expected, and apart from the painting problem, the components respond fine. Here is the smallest example I could get to exhibit this bug: public

When should we use console class?

由 三世轮回 提交于 2019-12-06 21:38:17
问题 I was reading about Console class, and in the very first line, it was written New to Java 6 and when we are running Java SE 6 from command line, then we are typically using console class object So, which means we are implicitly using console class through the command line ?? Then, I started looking for more detail about Console class and I found Input from console class in java and Console link. So, concluded some points Console class are only usable outside the IDE using System.console()

How to iterate through a list of objects and assign children?

由 冷暖自知 提交于 2019-12-06 15:58:42
I have a Location POJO that stores Location objects parsed in from a JSON file, which I want to map to a graph. Each node's location in the graph corresponds to it's id field, where id="1" is the start node and id="10" is the goal node. To solve this I adapted a Node class to include methods such as setWeight() , addChildLocation() etc , But I'm not sure how to create the graph from my list of locations. I know how to create the graph by hard coding the location's and calling addChildren, by doing the following, but not sure how to create it from a list of already available Location objects:
订阅 java-5