In a unit test project, I need some help figuring out how how I can hide 2 unnecessary parent nodes in marshaled XML? Can anyone help me figure out how to do it? My marshalled output looks like this: <suite> <suiteName>Suite 1</suiteName> <sauceURL>http://username-string:access-key-string@ondemand.saucelabs.com:80/wd/hub</sauceURL> <tests> <tes
在单元测试项目中,我需要一些帮助来弄清楚如何在编组XML中隐藏2个不必要的父节点? 任何人都可以帮我弄清楚如何做到这一点? 编组输出如下所示: <suite> <suiteName>Suite 1</suiteName> <sauceURL>http://username-string:access-key-string@ondemand.saucelabs.com:80/wd/hub</sauceURL> <tests> <test> <rowArgs> <arg> <e
I have interface: interface Identifable<T extends Serializable> { T getID(); } and class that implement this: public class Cat implements Identifable<Long> { public Long getID(){...}; } everything works fine. so far. Now I want to create GenericDAO, why I cannot create this?: public abstract GenericDAO<T extends Identifable<S>> { T getByID(S id); }
我有界面: interface Identifable<T extends Serializable> { T getID(); } 和实现这个的类: public class Cat implements Identifable<Long> { public Long getID(){...}; } 一切正常。 至今。 现在我想创建GenericDAO,为什么我不能创建它?: public abstract GenericDAO<T extends Identifable<S>> { T getByID(S id); } 我只能将GenericDAO声明为: public abstract Ge
In Java, there is a practice of declaring every variable (local or class), parameter final if they really are. Though this makes the code a lot more verbose, this helps in easy reading/grasping of the code and also prevents mistakes as the intention is clearly marked. What are your thoughts on this and what do you follow? I think it all has to do with good coding style. Of course you can w
在Java中,有一种做法是声明每个变量(本地或类),参数最终如果它们是真的。 虽然这使代码变得更加冗长,但这有助于轻松阅读/掌握代码,并且可以防止错误,因为意图清晰标记。 你对此有何想法?你有什么看法? 我认为这一切都与良好的编码风格有关。 当然,你可以在任何地方不使用大量final修饰语的情况下编写出性能良好,功能强大的程序,但是当你考虑它时...... 对所有不应改变的事物添加final只会缩小您(或下一位
I'm newbie in Java. So question might sound simple, but I'm stuck and can not figure out why this code returns null and 0.0 ? file: Transport.java public class Transport { private String name; private double price; public Transport(String name, double price) { this.name = name; this.price = price; } public String carName() { retur
我是Java新手。 所以问题可能听起来很简单,但我卡住了,不知道为什么这个代码返回null和0.0? 文件:Transport.java public class Transport { private String name; private double price; public Transport(String name, double price) { this.name = name; this.price = price; } public String carName() { return name; } public double carPrice(){
When using Spring, is it possible to set a property only if the value passed is not null? Example: <bean name="myBean" class="some.Type"> <property name="abc" value="${some.param}"/> </bean> The behavior I'm looking for is: some.Type myBean = new some.Type(); if (${some.param} != null) myBean.setAbc(${some.param}); The reason I need this is since abc has a default v
当使用Spring时,只有在传递的值不为null时才可以设置属性? 例: <bean name="myBean" class="some.Type"> <property name="abc" value="${some.param}"/> </bean> 我正在寻找的行为是: some.Type myBean = new some.Type(); if (${some.param} != null) myBean.setAbc(${some.param}); 我需要这个的原因是因为abc有一个默认值,我不想用null覆盖它。 而且我创建的Bean不在我的源代码控制之下 -
I'm using Hibernate Query by Example (QbE) with a pojo that have a lot of String properties, and also another properties like Boolean, Date, etc. The problem is that I'm creating a search page for that entity, where the user will can set filters values for all fields, but if the user leave any String field empty, Hibernate include this property into query, breaking the results. I know
我正在使用Hibernate Query by Example(QbE),其中pojo具有很多String属性,还有另一个属性,如Boolean,Date等。 问题是我正在为该实体创建一个搜索页面,用户可以在其中为所有字段设置过滤器值,但如果用户将任何字符串字段留空,Hibernate会将此属性包含在查询中,从而破坏结果。 我知道我可以通过属性检查属性,看它是否为空,并排除属性或设置为null。 但这似乎是一个丑陋的决议。 我想知道是否可以通用地检查所有
I'm trying to write a Java routine to evaluate simple math expressions from String values like: "5+3" "10-40" "10*3" I want to avoid a lot of if-then-else statements. How can I do this? 使用JDK1.6,您可以使用内置的JavaScript引擎。 import javax.script.ScriptEngineManager; import javax.script.ScriptEngine; import javax.script.ScriptException; public clas
我正在尝试编写一个Java例程来评估来自String值的简单数学表达式,如: "5+3" "10-40" "10*3" 我想避免很多if-then-else语句。 我怎样才能做到这一点? 使用JDK1.6,您可以使用内置的JavaScript引擎。 import javax.script.ScriptEngineManager; import javax.script.ScriptEngine; import javax.script.ScriptException; public class Test { public static void main(String[] args
I wonder why there is no common method to check for null value at java object level. What is the problem if the java.lang.Object class have had a method isNull to check for null value. 没有理由这样做,你检查null作为oleksii声明... if (foo == null) { } It is a sensible question as @jsn notes, but in the Java World the idea of an isNull is like an isTrue method. Just because Microsoft does it,
我想知道为什么没有通用的方法来检查Java对象级别的空值。 如果java.lang.Object类有一个方法isNull来检查空值,那么问题是什么。 没有理由这样做,你检查null作为oleksii声明... if (foo == null) { } @jsn指出这是一个明智的问题,但在Java世界中, isNull的想法就像isTrue方法。 只是因为微软这样做,并不是一个好主意。 ;) isNull只能返回false,因为您只能在非空引用上调用方法。 所以如果你可以调用isNull它必须
This question already has an answer here: Java Object Null Check for method 8 answers Apparently, you are actually asking how null checks are implemented under the hood. The answer is implementation specific. It could be different for different JVMs and / or execution platforms. (If you want to research the specific implementation on a specific JVM, I suggest you checkout the JVM source c
这个问题在这里已经有了答案: Java对象空检查方法8的答案 显然,你实际上正在问如何在引擎盖下实现null检查。 答案是具体实现。 对于不同的JVM和/或执行平台可能会有所不同。 (如果您想研究特定JVM上的特定实现,我建议您检出JVM源代码和/或让JIT编译器将已编译的本机代码转储出来供您检查。) 基本上有两种方法: 显式x == null测试通常会编译为一个指令序列,该指令序列将x的值与表示null的值进行比较。 这通常
In my code I have a org.apache.tapestry5.json.JSONObject named j . I want to read the property use-name from that Object: Boolean isUseName = (Boolean) j.opt("use-name"); The value can either be true, false or null (if the entry is not present in the JSONObject). Now I'd like to use isUseName for a conditional statement: if(!isUseName) {System.out.println("No Name to be used.")} T
在我的代码中,我有一个名为j的org.apache.tapestry5.json.JSONObject 。 我想从该对象读取属性use-name : Boolean isUseName = (Boolean) j.opt("use-name"); 该值可以是true,false或null(如果条目不存在于JSONObject中)。 现在我想使用isUseName作为条件语句: if(!isUseName) {System.out.println("No Name to be used.")} 如果“use-name”不在JSONObject中,这会给我一个NullPointerException。 一种方法是