JasperReport學習筆記4-查詢數據庫生成動態的報表（WEB）

分兩種方法 
第一種 
1.模版 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE jasperReport PUBLIC "//JasperReports//DTD Report Design//EN"
"http://jasperreports.sourceforge.net/dtds/jasperreport.dtd">
<jasperReport name="DBReport">
    <parameter name="hp" class="java.lang.Integer"></parameter>
    <queryString>
        <![CDATA[
            select tb.name as name,tb.age as age,tbs.marks as marks from jaspertb tb join jaspertbs tbs on(tb.id = tbs.tbid) where tb.id > $P{hp}
        ]]>
    </queryString>
    <field name="marks" class="java.lang.Integer"></field>
    <field name="name" class="java.lang.String"></field>
    <field name="age" class="java.lang.Integer"></field>
    <pageHeader>
        <band height="30">
            <staticText>
                <reportElement x="0" y="0" width="69" height="24" />
                <text><![CDATA[marks:]]></text>
            </staticText>

            <staticText>
                <reportElement x="140" y="0" width="79" height="24" />
                <text><![CDATA[name:]]></text>
            </staticText>

            <staticText>
                <reportElement x="280" y="0" width="69" height="24" />
                <text><![CDATA[age:]]></text>
            </staticText>

            <staticText>
                <reportElement x="420" y="0" width="69" height="24" />
                <text><![CDATA[you don't see this]]></text>
            </staticText>
        </band>
    </pageHeader>

    <detail>
        <band height="30">
            <textField>
                <reportElement x="0" y="0" width="69" height="24" />
                <textFieldExpression class="java.lang.Integer">
                    <![CDATA[$F{marks}]]>
                </textFieldExpression>
            </textField>
            <textField>
                <reportElement x="140" y="0" width="69" height="24" />
                <textFieldExpression class="java.lang.String">
                    <![CDATA[$F{name}]]>
                </textFieldExpression>
            </textField>
            <textField>
                <reportElement x="280" y="0" width="69" height="24" />
                <textFieldExpression class="java.lang.Integer">
                    <![CDATA[$F{age}]]>
                </textFieldExpression>
            </textField>
            <staticText>
                <reportElement x="420" y="0" width="69" height="24" />
                <text><![CDATA[If you don't see this, it didn't work]]></text>
            </staticText>
        </band>
    </detail>
</jasperReport>

2.把上面的JRXML文件生成JASPER文件，方便在WEB裏面的調用（可以用下面的方法先生成好，放到你知道的文件夾下面） 

JasperCompileManager.compileReportToFile("WebRoot\\report\\JasperReportSQL.xml","WebRoot\\report\\JasperReportSQL.jasper");

3.寫Servlet調用 

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.HashMap;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JasperRunManager;

public class DynamicCreateReportWithServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        Connection connection = null;
        //獲得輸出流
        ServletOutputStream servletOutputStream = response.getOutputStream();
        //獲得JASPER文件的輸入流,一定要知道你的文件的地方
        InputStream is = getServletConfig().getServletContext().getResourceAsStream("report\\JasperReportSQL.jasper");
        //生成Map對象傳數據
        HashMap hm =  new HashMap();
        hm.put("hp", new Integer(3));
        try {
            //連結JDBC
            Class.forName("com.mysql.jdbc.Driver");
            connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/jasperreportdb","root", "root");
            //生成相於的PDF輸入流,這個JasperRunManager對象還有很多種方法的,這只是一種
            JasperRunManager.runReportToPdfStream(is,servletOutputStream,hm, connection);
            //設置格式
            response.setContentType("application/pdf");
            servletOutputStream.flush();
            servletOutputStream.close();
            connection.close();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (JRException e) {
            e.printStackTrace();
        }
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        this.doGet(request, response);
    }

}

第二種方法 
1.這種方法JRXML文件裏面不用寫SQL 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE jasperReport PUBLIC "//JasperReports//DTD Report Design//EN"
"http://jasperreports.sourceforge.net/dtds/jasperreport.dtd">
<jasperReport name="DBReport">
    <field name="id" class="java.lang.Integer"></field>
    <field name="name" class="java.lang.String"></field>
    <field name="marks" class="java.lang.Integer"></field>

    <pageHeader>
        <band height="30">
            <staticText>
                <reportElement x="0" y="0" width="69" height="24" />
                <text><![CDATA[id:]]></text>
            </staticText>

            <staticText>
                <reportElement x="140" y="0" width="79" height="24" />
                <text><![CDATA[name:]]></text>
            </staticText>

            <staticText>
                <reportElement x="280" y="0" width="69" height="24" />
                <text><![CDATA[marks:]]></text>
            </staticText>

            <staticText>
                <reportElement x="420" y="0" width="69" height="24" />
                <text><![CDATA[you don't see this]]></text>
            </staticText>
        </band>
    </pageHeader>

    <detail>
        <band height="30">
            <textField>
                <reportElement x="0" y="0" width="69" height="24" />
                <textFieldExpression class="java.lang.Integer">
                    <![CDATA[$F{id}]]>
                </textFieldExpression>
            </textField>
            <textField>
                <reportElement x="140" y="0" width="69" height="24" />
                <textFieldExpression class="java.lang.String">
                    <![CDATA[$F{name}]]>
                </textFieldExpression>
            </textField>
            <textField>
                <reportElement x="280" y="0" width="69" height="24" />
                <textFieldExpression class="java.lang.Integer">
                    <![CDATA[$F{marks}]]>
                </textFieldExpression>
            </textField>
            <staticText>
                <reportElement x="420" y="0" width="69" height="24" />
                <text><![CDATA[If you don't see this, it didn't work]]></text>
            </staticText>
        </band>
    </detail>
</jasperReport>

2.同樣是用下面的方法生成JASPER文件 

JasperCompileManager.compileReportToFile("WebRoot\\report\\JasperReportSQLResult.xml","WebRoot\\report\\JasperReportSQLResult.jasper");

3.寫出Servlet 

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.HashMap;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JRResultSetDataSource;
import net.sf.jasperreports.engine.JasperRunManager;

public class DynamicCreateReportWithServletDateSource extends HttpServlet {

    private static final long serialVersionUID = 1L;

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        Connection connection = null;
        Statement statument = null;
        ResultSet resultSet = null;
        String sql = "select tb.name as name,tb.age as age,tbs.marks as marks from jaspertb tb join jaspertbs tbs";
        ServletOutputStream servletOutputStream = response.getOutputStream();
        InputStream is = getServletConfig().getServletContext().getResourceAsStream("report\\JasperReportSQLResult.jasper");
        try {
            Class.forName("com.mysql.jdbc.Driver");
            connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/jasperreportdb","root", "root");
            statument = connection.createStatement();
            resultSet = statument.executeQuery(sql);
            //這裏把ResultSet封裝到JRResultSetDataSource對象裏面了
            JasperRunManager.runReportToPdfStream(is,servletOutputStream,new HashMap(), new JRResultSetDataSource(resultSet));
            response.setContentType("application/pdf");
            servletOutputStream.flush();
            servletOutputStream.close();
            connection.close();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (JRException e) {
            e.printStackTrace();
        }
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        this.doGet(request, response);
    }

}

注意：JRXML文件裏面數據庫的字段都是用$F{marks},而parameter是用$P{xxxx}表示的 

，而parameter的值都是傳過去的那個HashMap裏面設置的

轉載自：http://langhua9527.iteye.com/blog/400435