Question

我正在使用下面显示的java代码在连接到我的计算机的HP DeskJet1000 USB打印机上打印文本文件。每当我运行此代码时，都会发送打印作业，但打印机不会打印任何内容。状态显示打印机正在打印，但它甚至没有进入页面。请帮忙！我的代码如下：

package printing;

import java.io.FileInputStream;
import javax.print.*;
import javax.print.attribute.HashPrintRequestAttributeSet;
import javax.print.attribute.PrintRequestAttributeSet;

/** @author Majid */
public class Printing {
    public static void main (String [] args) {
        // TODO code application logic here
        DocFlavor flavor = DocFlavor.INPUT_STREAM.AUTOSENSE;
        PrintRequestAttributeSet aset = new HashPrintRequestAttributeSet ();
        /* locate a print service that can handle it */
        PrintService [] pservices = PrintServiceLookup.lookupPrintServices (flavor, aset);
        /* create a print job for the chosen service */
        int printnbr = 0;
        DocPrintJob pj = pservices [printnbr].createPrintJob ();
        try {
            FileInputStream fis = new FileInputStream ("e:/fypdatabase/test.txt");
            Doc doc = new SimpleDoc (fis, flavor, null);
            //PrintJobWatcher pjDone = new PrintJobWatcher (pj);
            /* print the doc as specified */
            pj.print (doc, aset);
        }
        catch (Exception ex) {
            ex.printStackTrace ();
        }  
    }
}

Answer 1

@ moskiteau为什么你在

中硬编码[2]

DocPrintJob pj = pservices[2].createPrintJob();

而不是将 printer 的值作为pservices的索引？

DocPrintJob pj = pservices[printer].createPrintJob();

（对不起，如果这不是澄清这个问题的正确位置，但这是我在这里的第一个问题，并没有找到如何以任何其他方式提出这个问题）

Answer 2

您的代码实际上正在运行。但可能你正试图打印到错误的打印机......

试试这个：

package printing;

import java.io.FileInputStream;
import javax.print.*;
import javax.print.attribute.HashPrintRequestAttributeSet;
import javax.print.attribute.PrintRequestAttributeSet;

/** @author Majid */
public class Printing {

    public static void main (String [] args) {
        // TODO code application logic here
        DocFlavor flavor = DocFlavor.INPUT_STREAM.AUTOSENSE;
        PrintRequestAttributeSet aset = new HashPrintRequestAttributeSet ();
        /* locate a print service that can handle it */
        PrintService [] pservices = PrintServiceLookup.lookupPrintServices (flavor, aset);

        try {
            int printer = getPrinter(pservices);
            if(printer == -1) {
                throw new Exception("No network printer found");
            }
            DocPrintJob pj = pservices[2].createPrintJob();
            FileInputStream fis = new FileInputStream ("c:/Temp/test.txt");
            Doc doc = new SimpleDoc (fis, flavor, null);
            pj.print (doc, aset);
        }
        catch (Exception ex) {
            ex.printStackTrace ();
        } 
    }

    private int getPrinter(PrintService[] pservices) {
        int printer = -1;
        for(int i = 0; i<pservices.size(); i++) {
            if(pservices[i].getName().contains("\\\\")) {
                System.out.println("network printer: " + pservices[i].toString());   
                printer = i;
                break;
            }        
        }
        return printer;
    }
}

java打印代码无法正常工作

2 个答案: