System.out.println();是比较好的方法!
也可以写日志,来调试
也可以写日志,来调试
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也可以写日志,来调试在你想要的地方out.print();打印出结果,看看是不是你想要的。这不失为两种有效的方法!
jbuulder,不清楚,学习! hotenM(南京) 可否详细说?
jbuilder没用过。
和log文件了。
但好象感觉还是不爽呀!
必要时也可以用System.out.println()进行调试,找到系统报错的语句后,再分析可能的错误!
附带log.java文件
import java.io.*;
import java.util.*;
import java.text.SimpleDateFormat;public class log
{
private static String lf = System.getProperty("line.separator", "\n");
private static boolean isValid = true;
private static FileWriter logfile = null;
private static final String NOTICE = "NOTICE";
private static final String WARNING = "WARNING";
private static final String ERROR = "ERROR";
private static String CreateLogDate = "";
public static String ErrorMsg = ""; static
{
init();
}
private static String getDateString() {
SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMdd");
String s2 = formatter.format(new Date());
return s2;
}
private static void init() {
try {
String logFileString = "system_";
if (logFileString == null) {
throw new Exception ("");
}
CreateLogDate = getDateString();
logFileString += CreateLogDate+".log";
logfile = new FileWriter(logFileString,true);
} catch (Exception e) {
ErrorMsg = e.toString();
isValid = false;
} catch (Throwable t) {
isValid = false;
}
}
public static boolean note(String description) {
return log(NOTICE, description);
}
public static boolean warn(String description) {
return log(WARNING, description);
}
public static boolean error(String description) {
return log(ERROR, description);
}
public static boolean error(String description, Throwable t) {
return log(ERROR, description, t);
}
public static boolean error(Throwable t) {
return log(ERROR, "", t);
}
private static boolean log(String level, String description) {
return log(level, description, null);
}
private static boolean log(String level, String description, Throwable t)
{
if ( isValid )
{
Date date = new Date();
StringBuffer logEntry = new StringBuffer();
logEntry.append ( "[" );
logEntry.append ( date.toString() );
logEntry.append ( "] -- " );
logEntry.append ( level );
logEntry.append ( " -- " );
logEntry.append ( description );
logEntry.append ( lf );
if (t != null)
{
ByteArrayOutputStream ostr = new ByteArrayOutputStream();
PrintWriter out = new PrintWriter(ostr,true);
out.write(logEntry.toString());
out.write("\tException: ");
out.write(t.toString());
out.write(lf+"\tStack Trace follows:"+lf+"\t");
t.printStackTrace(out);
logEntry = new StringBuffer( ostr.toString() );
}
synchronized( logfile )
{
try {
// if(!CreateLogDate.startsWith(getDateString()))
// {
// logfile.close();
init();
// }
//ErrorMsg = logEntry.toString();
logfile.write(logEntry.toString(), 0, logEntry.length());
logfile.flush();
logfile.close();
} catch(IOException ioe) {
return false;
}
}
return true;
}
return false;
} public void destroy()
{
try {
logfile.close();
}
catch (Exception e)
{}
}
}查看时只要增加
log.note(sql);//其中sql为具体操作的字符串