小编Thu*_*fir的帖子

许多基于java的应用程序需要设置JAVA_HOME env变量.这个变量的目的是什么？

Java虚拟机和Dalvik虚拟机有什么区别？

在尝试获得@OneToMany之间的关系时Article,HeaderField我可能有不正确的映射,导致:

init:
Deleting: /home/thufir/NetBeansProjects/USENET/build/built-jar.properties
deps-jar:
Updating property file: /home/thufir/NetBeansProjects/USENET/build/built-jar.properties
compile:
run:
DEBUG: nntp: newsrc loading /home/thufir/.newsrc
DEBUG: nntp: newsrc load: 1 groups in 31ms
[EL Info]: 2012-07-31 02:05:05.677--ServerSession(8979162)--EclipseLink, version: Eclipse Persistence Services - 2.3.0.v20110604-r9504
[EL Info]: 2012-07-31 02:05:06.778--ServerSession(8979162)--file:/home/thufir/NetBeansProjects/USENET/build/classes/_USENETPU login successful
[EL Warning]: 2012-07-31 02:05:06.903--ServerSession(8979162)--Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.3.0.v20110604-r9504): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'usenet.HEADERFIELD' doesn't exist
Error Code: 1146
Call: ALTER TABLE HEADERFIELD DROP FOREIGN KEY FK_HEADERFIELD_ARTICLE_ID
Query: DataModifyQuery(sql="ALTER TABLE HEADERFIELD DROP …

如何使用 java.util.Logger 打印整个堆栈跟踪？(没有恼人的Netbeans).

该问题应该最初指定保留在 Java SE中.省略这个要求对我来说是一个错误.

-do-compile:
    [mkdir] Created dir: /home/thufir/NetBeansProjects/rainmaker/build/empty
    [mkdir] Created dir: /home/thufir/NetBeansProjects/rainmaker/build/generated-sources/ap-source-output
    [javac] Compiling 13 source files to /home/thufir/NetBeansProjects/rainmaker/build/classes
    [javac] /home/thufir/NetBeansProjects/rainmaker/src/model/TelnetEventProcessor.java:44: error: 'void' type not allowed here
    [javac]                 log.severe(npe.printStackTrace(System.out));
    [javac]                                               ^
    [javac] 1 error

BUILD FAILED

代码有错误:

package model;

import java.util.Observable;
import java.util.logging.Logger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class TelnetEventProcessor extends Observable {

    private static Logger log = Logger.getLogger(TelnetEventProcessor.class.getName());
    private String string = null;

    public TelnetEventProcessor() {
    }

    private void stripAnsiColors() {
        Pattern regex = …

什么mappedBy地图来？或者,相反,它应该映射到什么？

headers下面的字段@Entity Foo按照@OneToMany 文档进行映射？然后Foo将是一个包装javax.mail.Header？

package net.bounceme.dur.usenet.model;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.mail.Header;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.persistence.*;

@Entity
public class Articles implements Serializable {

    private static final long serialVersionUID = 1L;
    private static final Logger LOG = Logger.getLogger(Articles.class.getName());
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    @Column
    private String subject;

    @OneToMany(mappedBy="foo")  //a wrapper for Header is needed?
    private List<Header> headers = …

在Java中,查看NamedNodeMap接口,如何使用泛型进行迭代？它似乎使用Node而不是String,但我不太确定如何使用Node对象......

NamedNodeMap namedNodeMap = doc.getAttributes();
Map<String, String> stringMap = (Map<String, String>) namedNodeMap;
for (Map.Entry<String, String> entry : stringMap.entrySet()) {
  //key,value stuff here
}

是的,我可以看到如何迭代而不使用泛型和常规for循环,但我想使用上面的？成语？对于地图.当然,问题似乎是,尽管名称,NamedNodeMap实际上并没有实现Map接口!:(

猜猜你只需要咬紧牙关,做一些像:

/*
 * Iterates through the node attribute map, else we need to specify specific 
 * attribute values to pull and they could be of an unknown type
 */
private void iterate(NamedNodeMap attributesList) {
    for (int j = 0; j < attributesList.getLength(); j++) {
        System.out.println("Attribute: "
                + attributesList.item(j).getNodeName() + " = "
                + attributesList.item(j).getNodeValue()); …

如何在这个和这个构建文件可以使用providedCompile？

thufir@doge:~/NetBeansProjects/gradleEAR$ 
thufir@doge:~/NetBeansProjects/gradleEAR$ gradle clean

FAILURE: Build failed with an exception.

* Where:
Build file '/home/thufir/NetBeansProjects/gradleEAR/build.gradle' line: 40

* What went wrong:
A problem occurred evaluating root project 'gradleEAR'.
> Could not find method providedCompile() for arguments [javax:javaee-api:7.0] on object of type org.gradle.api.internal.artifacts.dsl.dependencies.DefaultDependencyHandler.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 12.721 secs
thufir@doge:~/NetBeansProjects/gradleEAR$ 

plugins { …

如何将MySql数据库与Firebase连接.这是用于实时数据更新并在浏览器上显示.已经创建了Firebase帐户并获得了配置代码.现在我想用Firebase连接我现有的基于MySql的数据库.

请帮忙

谢谢

我发现了这个问题,而另一个,这个有趣的是它引出了几个问题,至少对我而言:

相当开放的问题,但在哪里被jshell 限制？显然,GUI应用程序不在域中用于jshell解决方案或IDE替换:

超出范围的是图形界面和调试器支持.JShell API旨在允许IDE和其他工具中的JShell功能,但jshell工具并非旨在成为IDE.

维恩图或其他视觉效果的奖励积分.

当然,片段的大小应该是有限的.我更想问一下使用片段无法解决哪些问题.

也可以看看:

https://openjdk.java.net/jeps/222

https://openjdk.java.net/jeps/330

我不太确定这个错误消息是什么表明:

INFO:   visiting unvisited references
INFO:   visiting unvisited references
INFO:   visiting unvisited references
INFO:   visiting unvisited references
INFO:   EJB5181:Portable JNDI names for EJB Hello: [java:global/SalutationApp/SalutationApp-ejb/Hello, java:global/SalutationApp/SalutationApp-ejb/Hello!ejb.Hello]
INFO:   Loading application [SalutationApp#SalutationApp-war.war] at [SalutationApp-war]
INFO:   SalutationApp was successfully deployed in 976 milliseconds.
WARNING:   Context path from ServletContext: /SalutationApp-war differs from path from bundle: SalutationApp-war
INFO:   myRemoteMethod..

据我所知,似乎没有"application.xml"文件...已被弃用？

thufir@dur:~/NetBeansProjects/SalutationApp/dist$ 
thufir@dur:~/NetBeansProjects/SalutationApp/dist$ ll
total 16
drwxrwxr-x 2 thufir thufir 4096 Sep  9 01:42 ./
drwxrwxr-x 8 thufir thufir 4096 Sep  9 01:42 ../
-rw-rw-r-- 1 …