我有一个MessageDrivenBean，在import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.geom.Line2D;
import java.awt.geom.Path2D;
import java.awt.geom.Point2D;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JButton[] buttons = new JButton[]{
new JButton("1"),
new JButton("2"),
new JButton("3"),
new JButton("4"),};
private List<Connection> connections;
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.insets = new Insets(10, 10, 10, 10);
add(buttons[0], gbc);
gbc.gridx = 2;
gbc.gridy = 0;
add(buttons[1], gbc);
gbc.gridx = 1;
gbc.gridy = 1;
add(buttons[2], gbc);
gbc.gridx = 2;
gbc.gridy = 2;
add(buttons[3], gbc);
connections = new ArrayList<Connection>(25);
connections.add(new Connection(buttons[0], buttons[1]));
connections.add(new Connection(buttons[0], buttons[2]));
connections.add(new Connection(buttons[0], buttons[3]));
connections.add(new Connection(buttons[1], buttons[3]));
connections.add(new Connection(buttons[2], buttons[3]));
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(Color.RED);
for (Connection connection : connections) {
JButton source = connection.getSource();
JButton dest = connection.getDestination();
if (source.getX() == dest.getX()) {
// Same column...
g2d.drawLine(source.getX() + source.getWidth() / 2, source.getY(),
dest.getX() + source.getWidth() / 2, dest.getY());
} else if (source.getY() == dest.getY()) {
// Same row...
g2d.drawLine(source.getX(), source.getY() + source.getHeight() / 2,
dest.getX(), dest.getY() + dest.getHeight() / 2);
} else {
Path2D path = new Path2D.Double();
path.moveTo(horizontalCenter(source), verticalCenter(source));
path.curveTo(horizontalCenter(source), verticalCenter(dest),
horizontalCenter(source), verticalCenter(dest),
horizontalCenter(dest), verticalCenter(dest));
g2d.draw(path);
}
}
g2d.dispose();
}
protected double horizontalCenter(JComponent bounds) {
return bounds.getX() + bounds.getWidth() / 2d;
}
protected double verticalCenter(JComponent bounds) {
return bounds.getY() + bounds.getHeight() / 2d;
}
protected boolean hasIntersection(Line2D line, JComponent... exclude) {
List<JComponent> toExclude = Arrays.asList(exclude);
boolean intersects = false;
for (Component comp : getComponents()) {
if (!toExclude.contains(comp)) {
if (line.intersects(comp.getBounds())) {
System.out.println(line.getP1() + "-" + line.getP2() + " intersets with " + ((JButton)comp).getText() + "; " + comp.getBounds());
intersects = true;
break;
}
}
}
return intersects;
}
protected Line2D lineDownTo(JComponent from, JComponent to) {
return new Line2D.Double(horizontalCenter(from), from.getY(), horizontalCenter(from), verticalCenter(to));
}
protected Line2D lineAcrossTo(JComponent from, JComponent to) {
return new Line2D.Double(from.getX(), verticalCenter(from), horizontalCenter(to), verticalCenter(from));
}
protected Point2D centerOf(Rectangle bounds) {
return new Point2D.Double(bounds.getX() + bounds.getWidth() / 2, bounds.getY() + bounds.getHeight() / 2);
}
protected boolean canGoDownTo(Point2D startPoint, Point2D endPoint, JComponent to, JComponent from) {
Point2D targetPoint = new Point2D.Double(startPoint.getX(), endPoint.getY());
return !hasIntersection(new Line2D.Double(startPoint, targetPoint), to, from);
}
public class Connection {
private final JButton source;
private final JButton destination;
public Connection(JButton source, JButton destination) {
this.source = source;
this.destination = destination;
}
public JButton getSource() {
return source;
}
public JButton getDestination() {
return destination;
}
}
}
}
中运行，正在监听Glassfish 3.1.2。
当处理消息并且需要很长时间时，其他消息等待处理。
测试场景：发送大消息（需要大约30分钟处理）和250条小消息，而第一条消息仍在进行中。然后62个小消息在处理之前等待大消息。
MessageDrivenBean的bean池大小为4，在此测试中我没有使用预取限制。使用各种设置（例如ActiveMQ 5.9.0 Queue或?jms.prefetchPolicy.queuePrefetch=20，线程池最大队列大小2）的其他测试没有解决问题，总是有小消息等待大的。
我的问题是：是否有人知道如何配置...=2，MDB和/或ActiveMQ以避免此问题？或者这是轮询的典型场景，例如由glassfish？我知道，或者我可以使用两个队列和两个MDB（一个用于大型消息，一个用于较小的消息），但这意味着需要更改其他一些JMS通信方。
提前感谢您和最诚挚的问候， 马克