Jasper 報告預覽顯示字段中的數據，但在通過 java 生成報告時它會打印 NULL

Question

Jasperreport 成功生成 (JAsperTest.pdf )，但有以下異常，但它沒有在 ID 字段中打印任何整數值。 它在 ID 字段中僅打印 NULL。 但是 jasper 工具中的預覽顯示 ID 字段中的所有整數值，而不是通過 java 代碼生成的報告中。

"PM net.sf.jasperreports.engine.export.PdfGlyphRenderer determinePatchedItext
WARNING: Unpatched iText found, cannot use glyph rendering"

在其他論壇中提出了這個問題，但沒有找到解決方案。 請幫我解決。 我嘗試將 itext5.5.0 jar 刪除到 itext 7 jar 但導致錯誤。

包含在 lib 文件夾中的 Jar 文件： https : //imgur.com/lHZR60t

JasperTest.java

import java.io.File;
    import java.io.IOException;
    import java.util.HashMap;
    import java.util.Map;

    import net.sf.jasperreports.engine.JRDataSource;
    import net.sf.jasperreports.engine.JREmptyDataSource;
    import net.sf.jasperreports.engine.JRException;
    import net.sf.jasperreports.engine.JasperCompileManager;
    import net.sf.jasperreports.engine.JasperExportManager;
    import net.sf.jasperreports.engine.JasperFillManager;
    import net.sf.jasperreports.engine.JasperPrint;
    import net.sf.jasperreports.engine.JasperReport;
    public class JasperClass {

       public static void main(String[] args) throws JRException, IOException {

            // Compile jrxml file.
           JasperReport jasperReport = JasperCompileManager
                   .compileReport("C:/repo/JasperTest/Jaspertest.jrxml");

           // Parameters for report
           Map<String, Object> parameters = new HashMap<String, Object>();

           // DataSource
           // This is simple example, no database.
           // then using empty datasource.
           JRDataSource dataSource = new JREmptyDataSource();

           JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport,
                   parameters, dataSource);


           // Make sure the output directory exists.
           File outDir = new File("C:/repo/JasperTest");
           outDir.mkdirs();

           // Export to PDF.
           JasperExportManager.exportReportToPdfFile(jasperPrint,
                   "C:/repo/JasperTest/Jaspertest.pdf");

           System.out.println("Done!");
       }
    }

JasperTest.jrxml

<?xml version="1.0" encoding="UTF-8"?>
<!-- Created with Jaspersoft Studio version 6.4.0.final using JasperReports Library version 6.4.1  -->
<jasperReport xmlns="http://jasperreports.sourceforge.net/jasperreports" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports http://jasperreports.sourceforge.net/xsd/jasperreport.xsd" name="Jaspertest" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="98c6f0de-1e25-4ff3-b982-cfa45f54b507">
    <property name="com.jaspersoft.studio.data.sql.tables" value="Y2l0eSAsMTUsMTUsMTFlZThiNTgtMzM2OC00ZmQ3LWEzOTYtY2ZhMTM4MzllMjZhOw=="/>
    <property name="com.jaspersoft.studio.data.defaultdataadapter" value="Dataadaptertest.xml"/>
    <queryString language="SQL">
        <![CDATA[SELECT ID
FROM city]]>
    </queryString>
    <field name="ID" class="java.lang.Integer"/>
    <group name="ID">
        <groupExpression><![CDATA[$F{ID}]]></groupExpression>
    </group>
    <background>
        <band splitType="Stretch"/>
    </background>
    <title>
        <band height="75" splitType="Stretch">
            <staticText>
                <reportElement x="100" y="10" width="100" height="30" uuid="fe0a9fb7-deef-4393-a835-7cf9e41b8bef"/>
                <text><![CDATA[Test Successfull]]></text>
            </staticText>
        </band>
    </title>
    <columnHeader>
        <band height="63" splitType="Stretch">
            <staticText>
                <reportElement x="89" y="33" width="100" height="30" uuid="c2a5e228-a3f1-42fc-8064-688191cb7633"/>
                <text><![CDATA[ID]]></text>
            </staticText>
        </band>
    </columnHeader>
    <detail>
        <band height="46" splitType="Stretch">
            <textField>
                <reportElement x="89" y="10" width="100" height="30" uuid="126f1743-5bae-4e84-8bc6-9b36c2a808cc"/>
                <textFieldExpression><![CDATA[$F{ID}]]></textFieldExpression>
            </textField>
        </band>
    </detail>
</jasperReport>

Answer 1

問題解決了。 現在我可以在我的報告中看到數據。 正如亞歷克斯所說，我與 SQL 建立了連接。 謝謝你。 我在下面粘貼代碼以供參考。 avaCallJasperReport.java。

import java.io.File;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;

import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JasperCompileManager;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.JasperReport;
import net.sf.jasperreports.engine.export.JRPdfExporter;
import net.sf.jasperreports.export.ExporterInput;
import net.sf.jasperreports.export.OutputStreamExporterOutput;
import net.sf.jasperreports.export.SimpleExporterInput;
import net.sf.jasperreports.export.SimpleOutputStreamExporterOutput;
import net.sf.jasperreports.export.SimplePdfExporterConfiguration;

import conn.ConnectionUtils;

public class avaCallJasperReport {

    public static void main(String[] args) throws JRException,
            ClassNotFoundException, SQLException {

        String reportSrcFile = "C:/repo/JasperTest/Jaspertest.jrxml";

        // First, compile jrxml file.
        JasperReport jasperReport =    JasperCompileManager.compileReport(reportSrcFile);

        Connection conn = ConnectionUtils.getConnection();

        // Parameters for report
        Map<String, Object> parameters = new HashMap<String, Object>();

        JasperPrint print = JasperFillManager.fillReport(jasperReport,
                parameters, conn);

        // Make sure the output directory exists.
        File outDir = new File("C:/repo/JasperTest");
        outDir.mkdirs();

        // PDF Exportor.
        JRPdfExporter exporter = new JRPdfExporter();

        ExporterInput exporterInput = new SimpleExporterInput(print);
        // ExporterInput
        exporter.setExporterInput(exporterInput);

        // ExporterOutput
        OutputStreamExporterOutput exporterOutput = new SimpleOutputStreamExporterOutput(
                "C:/repo/JasperTest/FirstJasperReport.pdf");
        // Output
        exporter.setExporterOutput(exporterOutput);

        //
        SimplePdfExporterConfiguration configuration = new SimplePdfExporterConfiguration();
        exporter.setConfiguration(configuration);
        exporter.exportReport();

        System.out.print("tttt!");
    }
}

MySQLconnUtils.Java

package conn;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class MySQLconnUtils {



        public static Connection getMySQLConnection()
                throws ClassNotFoundException, SQLException {
            String hostName = "localhost";
            String dbName = "world";
            String userName = "root";
            String password = "root";
            return getMySQLConnection(hostName, dbName, userName, password);
        }

        public static Connection getMySQLConnection(String hostName, String dbName,
                String userName, String password) throws SQLException,
                ClassNotFoundException {

            Class.forName("com.mysql.jdbc.Driver");

            System.out.println("Get qq ... ");
            String connectionURL = "jdbc:mysql://" + hostName + ":3306/" + dbName;

            Connection conn = DriverManager.getConnection(connectionURL, userName,
                    password);
            return conn;
        }
    }

連接實用程序

package conn;

import java.sql.Connection;
import java.sql.SQLException;

public class ConnectionUtils {

    public static Connection getConnection() throws SQLException,
            ClassNotFoundException {

        // Using Oracle
        // You may be replaced by other Database.
        return MySQLconnUtils.getMySQLConnection();
    }

    //
    // Test Connection ...
    //
    public static void main(String[] args) throws SQLException,
            ClassNotFoundException {

        System.out.println("Get connection ... ");

        // Get a Connection object
        Connection conn = ConnectionUtils.getConnection();

        System.out.println("Get connection " + conn);

        System.out.println("Done!");
    }
}