JAVA
1、获取登陆用户
public static User getUser(HttpServletRequest request) {
Object obj = request.getSession().getAttribute("LOGON");
return obj == null ? null : (User) obj;
}
2、获取时间差（毫秒）
long startTime = System.currentTimeMillis();
conn = baseLogic.getConnection();
creditorReport.reportCreditorInfo(conn);
long endTime = System.currentTimeMillis();
log.info("本次数据导入【定时任务】执行共花费时间:"+(endTime-startTime)+"毫秒!");
3、格式化数字为 40,000.00
DecimalFormat format= new DecimalFormat("#,##0.00%");
String str=format.format((StringOperator.div(Double.parseDouble(dataArray[2]), Double.parseDouble(dataArray[1]), 4))); //通过件比例
public static double div(double v1,double v2,int scale){
if(scale<0){
throw new IllegalArgumentException("The scale must be a positive integer or zero"); }
BigDecimal b1 = new BigDecimal(Double.toString(v1)); BigDecimal b2 = new BigDecimal(Double.toString(v2));
return b1.divide(b2,scale,BigDecimal.ROUND_HALF_UP).doubleValue(); }
4、jdbc批量处理数据
List<YQInfo> list = null;
PreparedStatement ps =null;
try {
conn.setAutoCommit(false);
list = queryInfo(conn);
String sql = "INSERT INTO……";
ps = conn.prepareStatement(sql);
if(null!=list && list.size() > 0){
for (int i = 0; i < list.size(); i++) {
YQInfo yQInfo = list.get(i);
ps.setString(1, yQInfo.getLoanContractNo());
ps.addBatch();
if((i+1)%1000==0){
ps.executeBatch();
conn.commit();
ps.clearBatch();
}
}
ps.executeBatch();
}
conn.commit();
} catch (Exception e) {
e.printStackTrace();
log.info("逾期数据导入【定时任务】出现异常!");
log.error("逾期数据导入【定时任务】出现异常,开始删除异常数据!");
try {
//删除插入的数据
int result = deletetoDayData(conn);
log.error("共删除"+result+"条数据!");
conn.commit();
} catch (Exception e1) {
e1.printStackTrace();
}
throw new APSException(e);
}finally{
ObjectOperate.getInstance().ObjectFree(list);
ObjectOperate.getInstance().closConn(ps,conn);
}
/**
* 对象指空
* @param obj
*/
public void ObjectFree(Object ...obj) throws APSException {
try {
for (Object o : obj) {
if (null != o) {
o = null;
}
}
} catch (Exception e) {
StringBuffer erbuffer = new StringBuffer();
erbuffer.append("对象指空异常！");
log.error(erbuffer.toString(), e);
throw new APSException(erbuffer.toString(), e);
}
}
/**
* 关闭数据库
*
* @param rs
* @param st
* @param conn
*/
public void closConn(Object ... objects) throws APSException {
try {
for (Object obj : objects) {
if (obj instanceof ResultSet) {
((ResultSet) obj).close();
continue;
}
if (obj instanceof Statement) {
((Statement) obj).close();
continue;
}
if (obj instanceof PreparedStatement) {
((PreparedStatement) obj).close();
continue;
}
if (obj instanceof Connection) {
((Connection) obj).close();
continue;
}
}
} catch (Exception e) {
StringBuffer erbuffer = new StringBuffer();
erbuffer.append("关闭数据库连接异常！");
log.error(erbuffer.toString(), e);
throw new APSException(erbuffer.toString(), e);
}
}
5、给一段代码加锁
try {
synchronized (this) {
业务处理代码……
}
}
6、字符串判空
public static boolean isNull(String str) {
if (null == str || str.equals("")) {
return true;
}
return false;
}
7、删除指定路径下的文件
//删除目录下文件
public static void deletePath(String filepath) throws Exception {
File f = new File(filepath);//定义文件路径
if(f.exists() && f.isDirectory()){//判断是文件还是目录
//若有则把文件放进数组，并判断是否有下级目录
File delFile[]=f.listFiles();
int i =f.listFiles().length;
for(int j=0;j<i;j++){
if(delFile[j].isDirectory()){
deletePath(delFile[j].getAbsolutePath());//递归调用del方法并取得子目录路径
}
delFile[j].delete();//删除文件
}
}
}
8、创建目录
public static void mkDirs(String filePath) {
// 判断路径是否存在
File directory = new File(filePath.toString());
if (directory.exists() && directory.isDirectory()) {
} else {
// 如果不存在则创建目录
directory.mkdirs();
}
}
9、获取txt换行符
//获得换行符
private String getTxtNewLine() {
byte[] newLine = new byte[2];
newLine[0]=0x0d;
newLine[1]=0x0a;
return new String(newLine);
}
调用
fos.write((detailInfo.toString() + getTxtNewLine()).getBytes());
fos.flush();
detailInfo = null;
10、后台格式化数字
new DecimalFormat("##.00").format(amount);
11、结果集迭代
List<String> idCardList = new ArrayList<String>();
String[] cardArray = idCard.split(",");
for (String cardA : cardArray) {
idCardList.add(cardA);
}
12、本月一号到今天的数据
if (CommonMethod.isNull(appForm.getBeginDate())) {
queryCondition.append(" AND T.CREDIT_DATE>=TO_DATE('"+DateUtil.getFormatDateStr(new Date(), "yyyy-MM")+"-01','YYYY-MM-DD')");
}
if (CommonMethod.isNull(appForm.getEndDate())) {
queryCondition.append(" AND T.CREDIT_DATE<=TO_DATE('"+DateUtil.getFormatDateStr(new Date(), "yyyy-MM-dd")+" 23:59:59','YYYY-MM-DD hh24:mi:ss')");
}
13、通过request获取后台数据页面显示
后台
StringBuffer pathTemp = new StringBuffer();
pathTemp.append("会话已失效，请<a href='");
pathTemp.append(request.getContextPath());
pathTemp.append("/logon.do?method=reLogin' target='_top'>重新登录</a>！");
request.setAttribute("reason", pathTemp);
页面
<td align="left" class="red">
${errors }<br/>
<%=request.getAttribute("reason")%>
</td>
14、sevletPath
String sevletPath = request.getServletPath();
sevletPath = sevletPath.substring(1, sevletPath.indexOf("."));
15、请求路径（端口号）及方法
String methodName = mapping.getParameter();
logger.info(this.getClass().getName() + " 方法=" + methodValue + "被调用");
String requestStr= request.getRequestURL().toString();
String systemType = request.getRequestURI().split("/")[1];
int pos=requestStr.lastIndexOf(":");
String urlPort=requestStr.substring(pos+1,pos+6);