我想在OSGI包中开发日志系统，它可以将应用程序错误写入硬盘上的文件中。
这是激活者：
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.Constants;
import org.osgi.framework.Filter;
import org.osgi.framework.ServiceReference;
import org.osgi.framework.ServiceRegistration;
import org.osgi.util.tracker.ServiceTracker;
public class LoggingSystemApp implements BundleActivator {
LoggingSystemImpl log = null;
@Override
public void start(final BundleContext bc) throws Exception {
debug("Activator started");
ServiceRegistration registerService = bc.registerService(LoggingSystemImpl.class.getName(), new LoggingSystemImpl(), new Properties());
/* Start Logger System */
log = LoggingSystemImpl.getInstance();
log.start();
}
public void stop(BundleContext bc) throws Exception {
boolean ungetService = bc.ungetService(bc.getServiceReference(LoggingSystem.class.getName()));
st.close();
log.stop();
}
private void debug(String msg) {
System.out.println("JDBCBundleActivator: " + msg);
}
}
这是Logging系统的实现：
import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.nio.charset.Charset;
import java.sql.Connection;
import javax.sql.DataSource;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Calendar;
import java.util.Locale;
import org.DX_57.osgi.LS_27.api.LoggingSystem;
public class LoggingSystemImpl implements LoggingSystem {
public LoggingSystemImpl() {
}
public DataSource ds;
@Override
public void setDataSource(DataSource ds){
this.ds = ds;
}
private final static Calendar calendar = Calendar.getInstance();
private final static String user = System.getenv("USERNAME").toLowerCase();
private final static String sMonth = calendar.getDisplayName(Calendar.MONTH, Calendar.LONG, Locale.ENGLISH);
private final static int y = calendar.get(Calendar.YEAR);
// the name of the log file
//private final String logName = sysDrive + "\\fttb_web - " + sMonth.toLowerCase() + ", " + y + ".log";
private final String logName = "logger - " + sMonth.toLowerCase() + ", " + y + ".log";
private static boolean closed;
private static LoggingSystemImpl log = null;
private static BufferedWriter bw = null;
private static FileOutputStream fos = null;
private static OutputStreamWriter osw = null;
/* Utilialize Buffer and wait for data to write */
public void start() throws IOException{
log = LoggingSystemImpl.getInstance();
}
public void stop(){
log.close();
}
public void WriteLog(String WriteString){
log.writeln(WriteString);
}
public void LoggingSystemImpl() throws IOException
{
fos = new FileOutputStream(logName, true);
// set encoding to cyrillic (if available)
if (Charset.isSupported("windows-1251"))
{
osw = new OutputStreamWriter(fos, Charset.forName("windows-1251"));
}
else { osw = new OutputStreamWriter(fos); }
bw = new BufferedWriter(osw, 2048); // 2Mb buffer
}
// intro header for log session
public static synchronized LoggingSystemImpl getInstance() throws IOException
{
boolean exc = false;
try
{
if (log == null || closed)
{
log = new LoggingSystemImpl();
closed = false;
log.writeln("logged in.");
log.nl();
}
}
// catch(IOException x) { exc = true; throw x; }
catch(Exception x) { exc = true; x.printStackTrace(); }
finally
{
if (exc)
{
try
{
if (fos != null) { fos.close(); fos = null; }
if (osw != null) { osw.close(); fos = null; }
if (bw != null) { bw.close(); bw = null; }
}
catch(Exception x) { x.printStackTrace(); }
}
}
return log;
}
public synchronized void nl()
{
try { bw.newLine(); }
catch(IOException x) {x.printStackTrace();}
}
public synchronized void nl(int count)
{
try
{
for (int i = 0; i < count; i++) bw.newLine();
}
catch(IOException x) {x.printStackTrace();}
}
public synchronized void writeln(String s)
{
try { bw.write(getTime() + ": " + s); bw.newLine(); }
catch(IOException x) {x.printStackTrace();}
}
public synchronized void write(String s)
{
try { bw.write(s); }
catch (IOException x) {x.printStackTrace();}
}
public synchronized void close()
{
try
{
if (bw != null)
{
writeln("logged out.");
nl();
bw.flush();
bw.close();
closed = true;
fos = null;
osw = null;
bw = null;
}
}
catch(IOException x) { x.printStackTrace(); }
}
public synchronized boolean isClosed() { return closed; }
public synchronized void writeException(Exception x)
{
writeln("");
write("\t" + x.toString()); nl();
StackTraceElement[] ste = x.getStackTrace();
int j = 0;
for (int i = 0; i < ste.length; i++)
{
if (i < 15) { write("\t\tat " + ste[i].toString()); nl(); }
else { j++; }
}
if (j > 0) { write("\t\t... " + j + " more"); nl(); }
nl(2);
}
private String getTime()
{
Calendar c = Calendar.getInstance();
int month = c.get(Calendar.MONTH) + 1;
int d = c.get(Calendar.DAY_OF_MONTH);
int h = c.get(Calendar.HOUR_OF_DAY);
int m = c.get(Calendar.MINUTE);
int s = c.get(Calendar.SECOND);
int y = c.get(Calendar.YEAR);
String dd = d < 10 ? "0"+d : ""+d;
String hh = h < 10 ? "0"+h : ""+h;
String mm = m < 10 ? "0"+m : ""+m;
String ss = s < 10 ? "0"+s : ""+s;
String sm = month < 10 ? "0"+month : ""+month;
return user + " [" + y + "." + sm + "." + dd + " " + hh + ":" + mm + ":" + ss + "]";
}
}
当我尝试在Netbeans中编译代码时，我收到此错误：
COMPILATION ERROR :
-------------------------------------------------------------
org/DX_57/osgi/LS_27/impl/LoggingSystemImpl.java:[34,7] error: LoggingSystemImpl is not abstract and does not override abstract method SessionRegister(String,String,String) in LoggingSystem
1 error
我如何解决这个问题？
祝福
P.S 这是界面的代码
public interface LoggingSystem {
public void setDataSource(DataSource ds);
}
EDIT 你能告诉我你在代码中看到任何其他错误，尤其是Activator类吗？
答案 0 :(得分：4)
您必须在班级中实施上述方法。消息说你的类不抽象总线没有具体实现其父母的所有抽象方法。
答案 1 :(得分：3)
嗯，错误信息很清楚。您可以将LoggingSystemImpl声明为abstract，也可以实现缺少的方法 - SessionRegister(String,String,String)。
原因是接口LoggingSystem声明了方法SessionRegister(String,String,String)。因为它没有实现，所以需要在所有非抽象的子代中实现，包括你的类。
快速解决方法是：
public class LoggingSystemImpl implements LoggingSystem {
void SessionRegister(String,String,String)
{ //dummy implementation
}
//other methods
}