小编oli*_*olz的帖子

我试图连接和逗号删除(或空格)列表并投影它.我在下面有一些示例代码.

public class Friend
{
    public string Name { get; set; }
}

public class Person
{
    public int PersonID { get; set; }
    public string FirstName { get; set; }
    public string Surname { get; set; }
    List<Friend> Friends { get; set; }
}

public class ProjectedPerson
{
    public int PersonID { get; set; }
    public string FirstName { get; set; }
    public string Surname { get; set; }
    public string FriendsList { get; set; }
}

public class …

嗨,我想阅读包含使用java的德语字符的网页内容,遗憾的是,德语字符显示为奇怪的字符.任何帮助请在这里是我的代码:

String link = "some german link";

            URL url = new URL(link);
            BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
            String inputLine;
            while ((inputLine = in.readLine()) != null) {
                System.out.println(inputLine);
            }

运行我的应用程序时遇到以下异常：

我正在使用jboss：5.1.1和jdk 1.6。

01:50:04,828 ERROR [[HelloWorld]] Servlet.service() for servlet HelloWorld threw exception
java.util.ServiceConfigurationError: javax.xml.ws.spi.Provider: Provider org.jboss.ws.core.jaxws.spi.ProviderImpl not a subtype
    at java.util.ServiceLoader.fail(Unknown Source)
    at java.util.ServiceLoader.access$300(Unknown Source)
    at java.util.ServiceLoader$LazyIterator.next(Unknown Source)
    at java.util.ServiceLoader$1.next(Unknown Source)
    at javax.xml.ws.spi.Provider.getProviderUsingServiceLoader(Provider.java:146)
    at javax.xml.ws.spi.Provider.provider(Provider.java:106)
    at javax.xml.ws.Service.<init>(Service.java:57)
    at com.service_instance.ServiceInstance.<init>(ServiceInstance.java:50)
    at com.getBusinessApp(CMDB.java:239)
    at com.test.HelloWorld.doGet(HelloWorld.java:51)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:235)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:190)
    at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:92)
    at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.process(SecurityContextEstablishmentValve.java:126)
    at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:70)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:330)
    at …

为什么这段代码可能有空指针访问？

    Object v = (RuntimeException) null;
    throw (RuntimeException) v;

为什么这不是？

    throw (RuntimeException) null;

我正在尝试设置小数值,下面是我的输入字符串

String rate="1.000000000";

转换为double:

Double converted=Double.valueOf(rate);
DecimalFormat format=new DecimalFormat("#.########"); //Setting decimal points to 8

System.out.println("ouput"+format.format(rate)); //Giving output as 1.

我不明白该怎么做,请提示任何提示.

问候,

Chaitu

我正在使用net bean在Windows环境中开发我的应用程序.我在XML文件夹中有一个xml文件(在网页文件夹下).我使用以下代码来读取xml文件:

String path=new File("XML/TableNamesAndColumnNames.xml").getAbsolutePath();

但它没有找到任何文件..因为我得到的路径像 -

"C:\Documents and Settings\rajesh\My Documents\NetBeansProjects\ReportOfReuls\XML\TableNamesAndColumnNames.xml"

但如果我使用反斜杠,即:

"C:/Documents and Settings/rajesh/MyDocuments/NetBeansProjects/ReportOfReuls/web/XML/TableNamesAndColumnNames.xml" 

我正在获取文件..是Net Beans或Windows的问题..

请任何人建议如何解决这个问题

提前致谢.拉吉

我已经检查了几乎所有类型的对象数组的声明.请建议所需的更改.此代码给我一个空指针异常,如下所示:

objarray.main(objarray.java:33)中线程"main"java.lang.NullPointerException中的异常

import java.util.*;
class Prod {
    private int    pno, pcost;
    private String pname;

    void accept() {
        Scanner sc = new Scanner( System.in );
        System.out.println( "Enter pno" );
        pno = sc.nextInt();
        System.out.println( "Enter pname" );
        pname = sc.next();
        System.out.println( "Enter pcost" );
        pcost = sc.nextInt();
    }

    void print() {
        System.out.println( pno + "\t" + pname + "\t" + pcost );
    }
}

class objarray {
    public static void main( String[] args ) {
        int i;
        Prod[] p = new Prod[3]; …