【发布时间】：2016-12-27 17:46:33
【问题描述】：
请帮助尝试使用此代码在热敏打印机中打印，我的系统托盘中有打印作业，但我的热敏打印机无法打印。 PrintReceiptUtil 类：
import java.awt.JobAttributes;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.print.Doc;
import javax.print.DocFlavor;
import javax.print.DocPrintJob;
import javax.print.PrintException;
import javax.print.PrintService;
import javax.print.PrintServiceLookup;
import javax.print.SimpleDoc;
import javax.print.attribute.HashPrintRequestAttributeSet;
import javax.print.attribute.PrintRequestAttributeSet;
import javax.print.attribute.standard.Copies;
import javax.print.event.PrintJobAdapter;
import javax.print.event.PrintJobEvent;
public static void doPrintReceipt() throws IOException, PrintException{
String defaultPrinter = PrintServiceLookup.lookupDefaultPrintService().getName();
System.out.println("Default printer: " + defaultPrinter);
PrintService service = PrintServiceLookup.lookupDefaultPrintService();
// prints the famous hello world! plus a form feed
InputStream is = new ByteArrayInputStream("hello world!\f".getBytes("UTF8"));
PrintRequestAttributeSet pras = new HashPrintRequestAttributeSet();
pras.add(new Copies(1));
DocFlavor flavor = DocFlavor.INPUT_STREAM.AUTOSENSE;
Doc doc = new SimpleDoc(is, flavor, null);
DocPrintJob job = service.createPrintJob();
PrintJobWatcher pjw = new PrintJobWatcher(job);
job.print(doc, pras);
pjw.waitForDone();
is.close();
}
}
PrintJobWatcher 类：为了监控打印作业，我可以“打印完成”，但我的热敏打印机不打印任何东西
import javax.print.DocPrintJob;
import javax.print.event.PrintJobAdapter;
import javax.print.event.PrintJobEvent;
public PrintJobWatcher(DocPrintJob job){
job.addPrintJobListener(new PrintJobAdapter() {
public void printJobCanceled(PrintJobEvent pje) {
allDone();
}
public void printJobCompleted(PrintJobEvent pje) {
allDone();
}
public void printJobFailed(PrintJobEvent pje) {
allDone();
}
public void printJobNoMoreEvents(PrintJobEvent pje) {
allDone();
}
void allDone() {
synchronized (PrintJobWatcher.this) {
done = true;
System.out.println("Printing done ...");
PrintJobWatcher.this.notify();
}
}
});
}
public synchronized void waitForDone() {
try {
while (!done) {
wait();
}
} catch (InterruptedException e) {
}
}
}
【问题讨论】：
-
您可能需要添加一些缩进以使其更易于阅读。
-
您的 PrintJobListener 对每个最终结果案例都执行相同的操作。您可能应该为每个案例添加不同的案例，这样如果 printJobFailed 被抛出，您实际上会知道它失败了。