小编Naa*_*aaN的帖子

我试图对我的ArrayList进行排序.

java.util.ArrayList arList= new java.util.ArrayList();  
   arList=getList();    
   java.util.Collections.sort(arList);

我的getList()函数在这里

public ArrayList getList() throws Exception
{
ArrayList listItems = new ArrayList();
//Query executing here..............!
            while (rs.next()) 
                {
                HashMap hashList = new HashMap();
                hashList.put("name",rs.getString(1));
                hashList.put("id",rs.getBigDecimal(2));
                listItems.add(hashList);
                }
          return listItems;
}

但我面临错误:java.lang.ClassCastException:java.util.HashMap无法强制转换为java.lang.Comparable

尝试使用以下代码编写excel文件

public static void main(String[] args) 
    {
          XSSFWorkbook workbook = new XSSFWorkbook(); 

            XSSFSheet sheet = workbook.createSheet("Book Data");

            Map<String, Object[]> data = new TreeMap<String, Object[]>();
            data.put("1", new Object[] {"ID", "NAME", "LASTNAME"});
            for(int i=2;i<100000;i++)
            {               
                data.put(String.valueOf(i), new Object[] {i, "Name"+i, "LastName"+i});
            }

            Set<String> keyset = data.keySet();
            int rownum = 0;
            for (String key : keyset)
            {
                Row row = sheet.createRow(rownum++);
                Object [] objArr = data.get(key);
                int cellnum = 0;
                for (Object obj : objArr)
                {
                   Cell cell = row.createCell(cellnum++);
                   if(obj instanceof String) …

我试图xlsx使用Apache POI 将报告导出为格式化.以下是用于的代码.

public static void main(String[]args){
        try{
            XSSFWorkbook wb=new XSSFWorkbook();
            XSSFSheet sheet = wb.createSheet("new sheet");

            XSSFRow rowhead= sheet.createRow((short)0);
            rowhead.createCell((short) 0).setCellValue("column1");
            rowhead.createCell((short) 1).setCellValue("column2");
            rowhead.createCell((short) 2).setCellValue("column3");
            rowhead.createCell((short) 3).setCellValue("column4");
            rowhead.createCell((short) 4).setCellValue("column5");
                 System.out.println("im here");
            Class.forName("oracle.jdbc.driver.OracleDriver");
            Connection con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:...,....);
            Statement st=con.createStatement();         
            System.out.println("im here1");
            ResultSet rs=st.executeQuery("SELECT * FROM table3 ");
            System.out.println("im here2");         
            int i=1;
            while(rs.next()){
                XSSFRow row= sheet.createRow((short)i);
                row.createCell((short) 0).setCellValue(rs.getString("column1"));
                row.createCell((short) 1).setCellValue(rs.getString("column2"));
                row.createCell((short) 2).setCellValue(rs.getString("column3"));
                row.createCell((short) 3).setCellValue(rs.getString("column4"));
                row.createCell((short) 4).setCellValue(rs.getString("column5"));
                i++;
            }

            FileOutputStream fileOut = new FileOutputStream(new File("E:/report.xlsx"));
            wb.write(fileOut);
            fileOut.close();
            System.out.println("Your excel file has …

当按下 ESC 时，我试图调用一个函数使屏幕再次处于全屏模式。（也就是说，当按下 ESC 时，屏幕进入正常模式。我需要再次使其处于全屏模式）。识别出 ESC 单击事件再次调用全屏功能，例如

$(document).ready(function (){
var screen_change_events = "webkitfullscreenchange mozfullscreenchange fullscreenchange MSFullscreenChange";
$(document).on(screen_change_events, function () {
if (!window.screenTop && !window.screenY) {
$("iframe")['webkitRequestFullScreen'](); // Identified that ESC is triggered.So need to make it again fullscreen mode
}else{
//alert("no")
}
});
});

但出现以下错误。

Uncaught TypeError: $(...).webkitRequestFullScreen is not a function

例如something:8000/something.jsp?param1=update&param2=1000&param3=SearchString%&param4=3,在传递我的网址时,我收到以下错误:

Bad Request

Your browser sent a request that this server could not understand.

我知道SearchString%我需要传递哪个作为参数,有问题.那么如何在URL中传递包含'%'的参数？

我限制我JTextFields只接受数字.我正在使用以下代码.

  // my textboxes
  t1=new JTextField(10);
  t2=new JTextField(10);
  t3=new JTextField(10);

  // for the first one
  t1.addKeyListener(new KeyAdapter() {
        public void keyTyped(KeyEvent e) {
          char c = e.getKeyChar();
          if (!((c >= '0') && (c <= '9') ||
             (c == KeyEvent.VK_BACK_SPACE) ||
             (c == KeyEvent.VK_DELETE))) {
            getToolkit().beep();
            e.consume();
          }
        }
      });

假设我有20个texboxes需要相同的验证检查.那么我们需要写这个代码20次吗？我可以写一个通用的方法来实现它吗？我是新来的Swing.

我对以下不匹配感到困惑.

Select table_name, Num_Rows 
from all_tables 
where OWNER = 'OWNER_NAME' and table_name='TABLE_NAME1';

给了我一个结果401.

select count(*) from TABLE_NAME1

给了我一个数200.在尝试时TABLE_NAME2,两者都返回相同的值.
这里发生了什么？

我试图在excel表中添加一些样式,我使用apache poi生成.这是代码,我试图在BOLD中创建第一行.

    SXSSFWorkbook wb=new SXSSFWorkbook();
    Sheet sheet = wb.createSheet("Excelx");

    Row row= sheet.createRow((short)0);
    row.createCell((short) 0).setCellValue("SRNum");
    row.createCell((short) 1).setCellValue("Name");         
    CellStyle cs = wb.createCellStyle();
    Font f = wb.createFont();
    f.setFontHeightInPoints((short) 20);
    f.setBoldweight(Font.BOLDWEIGHT_BOLD);
    cs.setFont(f);
    row.setRowStyle(cs);

但是,第一行仍未改为BOLD.

我试图使用以下查询从表中获取最后一条记录。

SELECT *
  FROM TABLE1
 WHERE ROWID IN (SELECT MAX (ROWID) FROM TABLE1);

当我检查时ROWID，

值是 AAAZA5eAFAAA7AAAA

还有一些其他的价值MIN(ROWID)。

pseudocolumn这里如何对此进行评估？还提到了Oracle数据库不保证此类列的值是有效的rowid。因此，ROWID值在架构内不一定是唯一的吗？

根据文档： 数据库中的每一行都有一个地址。您可以通过查询伪列ROWID来检查行地址。该伪列的值是代表每行地址的字符串。这些字符串的数据类型为ROWID。您还可以创建包含具有ROWID数据类型的实际列的表和集群。Oracle数据库不保证此类列的值是有效的rowid。

我在尝试使用jasper生成excel报告时在WebSphere中获得以下异常.

 ThreadMonitor W   WSVR0605W: Thread "WebContainer : 0" (00000029) has been active for 647279 milliseconds and may be hung.  There is/are 1 thread(s) in total in the server that may be hung.

尝试将默认线程池大小从20增加到50,并将WebContainer池大小从50增加到150.不起作用.

任何解决方案.

我有一个ResultSet包含300K记录,我正在执行以下操作来迭代它(以及其他操作一旦收集).此过程大约需要2分钟才能完成.有没有办法优化它？

Map<String,Map<String,String>> internalMap  = new HashMap<String,Map<String,String>>(); 

while (resultSet.next()) {
    final Integer val1 = resultSet.getInt("val1");
    final String val2 = resultSet.getString("val2");
    final String val3 = resultSet.getString("val3");
    final String val4 = resultSet.getString("val4");
    final String type = resultSet.getString("type");
    final String id = resultSet.getString("id");

    addIntern(internalMap,val2,val1,val3,val4,type,id);
}

以及addIntern上面引用的方法

private static void addIntern(Map<String,Map<String,String>> internalMap, String val2, Integer val1,
    String val3,String val4,String type,String id) {
    String key = id+"##"+val4;
    if (internalMap.get(key) == null) {
        internalMap.put(key, new HashMap<String,String>());
    }
    internalMap.get(key).put("val3", val3);
    internalMap.get(key).put("val2", val2);


    if("create".equals(type)){
        internalMap.get(key).put("create", …

我试图通过基本身份验证获取 url。我设置了用户/密码，如下所示。同样的凭证在邮递员中工作。

String RELATIVE_IDENTITY_URL  = "http://my_url/api/core/v3/people/email/abc@example.com";
    RestTemplate restTemplate;
    Credentials credentials;

    //1. Set credentials
    credentials = new UsernamePasswordCredentials("admin", "admin");

    CredentialsProvider credsProvider = new BasicCredentialsProvider();
    credsProvider.setCredentials( AuthScope.ANY, credentials);

    //2. Bind credentialsProvider to httpClient
    HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();
    httpClientBuilder.setDefaultCredentialsProvider(credsProvider);
    CloseableHttpClient httpClient = httpClientBuilder.build();

    HttpComponentsClientHttpRequestFactory factory = new  
            HttpComponentsClientHttpRequestFactory(httpClient);

    //3. create restTemplate
    restTemplate = new RestTemplate();
    restTemplate.setRequestFactory(factory);

    //4. restTemplate execute
    String url = RELATIVE_IDENTITY_URL;

    String xml = restTemplate.getForObject(url,String.class); 
    System.out.println("Done");

我认为凭据设置不正确。这里有什么问题。？错误：

Exception in thread "main" org.springframework.web.client.HttpClientErrorException: 401 Unauthorized
    at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:91)
    at org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:667)
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:620)
    at …