JasperReports 多数据源

最后修改日期：2024 年 2 月 12 日

JasperReports 多数据源教程展示了如何使用 JasperReports 库生成包含多个数据源的报告。

JasperReports 是一个开源报告库。它可以创建各种格式的报告，包括 PDF、HTML、XLS 或 CSV。JasperReports 创建面向页面、可直接打印的文档。

JasperReports 多数据源示例

下面的应用程序在一个报告中显示来自两个不同数据源的数据。

pom.xml
src
└── main
    ├── java
    │   └── com
    │       └── zetcode
    │           ├── model
    │           │   ├── Car.java
    │           │   └── Country.java
    │           └── main
    │               ├── CommandLineRunner.java
    │               └── JasperMultipleDataSources.java
    └── resources
        └── report2.xml

这是项目结构。

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
         http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.zetcode</groupId>
    <artifactId>multipledatasets</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
        <exec.mainClass>com.zetcode.main.CommandLineRunner</exec.mainClass>
    </properties>

    <dependencies>

        <dependency>
            <groupId>net.sf.jasperreports</groupId>
            <artifactId>jasperreports</artifactId>
            <version>6.9.0</version>
        </dependency>

    </dependencies>

</project>

Maven pom.xml 文件包含 jasperreports 依赖项。

com/zetcode/model/Car.java

package com.zetcode.model;

public class Car {

    private Long id;
    private String name;
    private int price;

    public Car() {}

    public Car(Long id, String name, int price) {
        this.id = id;
        this.name = name;
        this.price = price;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "Car{" + "id=" + id + ", name=" +
                name + ", price=" + price + '}';
    }
}

这是一个 Car bean 类。它包含汽车 ID、名称和价格属性。

com/zetcode/model/Country.java

package com.zetcode.model;

public class Country {

    private Long id;
    private String name;
    private int population;

    public Country(Long id, String name, int population) {
        this.id = id;
        this.name = name;
        this.population = population;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getPopulation() {
        return population;
    }

    public void setPopulation(int population) {
        this.population = population;
    }
}

这是一个 Country bean 类。它包含国家 ID、名称和人口属性。

src/resources/report2.xml

<?xml version = "1.0" encoding = "UTF-8"?>
<!DOCTYPE jasperReport PUBLIC "//JasperReports//DTD Report Design//EN"
   "http://jasperreports.sourceforge.net/dtds/jasperreport.dtd">

<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="freport" pageWidth="595" pageHeight="842"
              columnWidth="555" leftMargin="20" rightMargin="20"
              topMargin="20" bottomMargin="20">

<style name="field" fontSize="11" />
<style name="textRight" style="field" hAlign="Right" />

<subDataset name="dataset1">
    <field name="id" class="java.lang.Long"/>
    <field name="name" class="java.lang.String"/>
    <field name="price" class="java.lang.Integer"/>
</subDataset>

<subDataset name="dataset2">
    <field name="id" class="java.lang.Long"/>
    <field name="name" class="java.lang.String"/>
    <field name="population" class="java.lang.Integer"/>
</subDataset>

<parameter name="datasource1" class="java.util.List"/>
<parameter name="datasource2" class="java.util.List"/>

<detail>
    <band height="15">

        <componentElement>
            <reportElement x="0" y="0" width="100" height="15"/>
            <jr:list xmlns:jr="http://jasperreports.sourceforge.net/jasperreports/components"
                        xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports/components
                                            http://jasperreports.sourceforge.net/xsd/components.xsd">

                <datasetRun subDataset="dataset2">
                    <dataSourceExpression><![CDATA[new net.sf.jasperreports.engine.data.JRBeanCollectionDataSource($P{datasource2})]]></dataSourceExpression>
                </datasetRun>

                <jr:listContents height="15" width="220">
                    <textField>
                        <reportElement x="0" y="0" width="20" height="15" style="field" />

                        <textElement />

                        <textFieldExpression class="java.lang.Long"><![CDATA[$F{id}]]></textFieldExpression>
                    </textField>

                    <textField>
                        <reportElement x="50" y="0" width="80" height="15" style="field" />

                        <textElement />

                        <textFieldExpression class="java.lang.String"><![CDATA[$F{name}]]></textFieldExpression>
                    </textField>

                    <textField>
                        <reportElement x="130" y="0" width="80" height="15" style="textRight" />
                        <textElement />

                        <textFieldExpression class="java.lang.Integer"><![CDATA[$F{population}]]></textFieldExpression>
                    </textField>

                </jr:listContents>
            </jr:list>
        </componentElement>

        <componentElement>
            <reportElement x="250" y="0" width="100" height="15"/>
            <jr:list xmlns:jr="http://jasperreports.sourceforge.net/jasperreports/components"
                        xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports/components
                                            http://jasperreports.sourceforge.net/xsd/components.xsd">

                <datasetRun subDataset="dataset1">
                    <dataSourceExpression><![CDATA[new net.sf.jasperreports.engine.data.JRBeanCollectionDataSource($P{datasource1})]]></dataSourceExpression>
                </datasetRun>

                <jr:listContents height="15" width="220">
                    <textField>
                        <reportElement x="0" y="0" width="20" height="15" style="field" />

                        <textElement />

                        <textFieldExpression class="java.lang.Long"><![CDATA[$F{id}]]></textFieldExpression>
                    </textField>

                    <textField>
                        <reportElement x="50" y="0" width="80" height="15" style="field" />

                        <textElement />

                        <textFieldExpression class="java.lang.String"><![CDATA[$F{name}]]></textFieldExpression>
                    </textField>

                    <textField>
                        <reportElement x="130" y="0" width="80" height="15" style="textRight" />
                        <textElement />

                        <textFieldExpression class="java.lang.Integer"><![CDATA[$F{price}]]></textFieldExpression>
                    </textField>

                </jr:listContents>
            </jr:list>
        </componentElement>

    </band>
</detail>

</jasperReport>

这是报告模板文件。该报告包含两个列表组件。列表组件从传递给报告的列表参数加载数据。

<subDataset name="dataset1">
    <field name="id" class="java.lang.Long"/>
    <field name="name" class="java.lang.String"/>
    <field name="price" class="java.lang.Integer"/>
</subDataset>

<subDataset name="dataset2">
    <field name="id" class="java.lang.Long"/>
    <field name="name" class="java.lang.String"/>
    <field name="population" class="java.lang.Integer"/>
</subDataset>