JAVA如何生成不是很规则的XML文件

Question

从java对象到xml不是难事，用xstream就可以，但是这是生成的规则的xml文件，如果有这样一个文件呢？

 

<graph caption="Monthly Unit Sales" xAxisName="Month" yAxisName="Units" decimalPrecision="0" formatNumberScale="0">
     <set name="Jan" value="462" color="AFD8F8" hoverText="Janssss.xxx" /> 
     <set name="Feb" value="857" color="F6BD0F" /> 
     <set name="Mar" value="671" color="8BBA00" /> 
     <set name="Apr" value="494" color="FF8E46" /> 
     <set name="May" value="761" color="008E8E" /> 
     <set name="Jun" value="960" color="D64646" /> 
     <set name="Jul" value="629" color="8E468E" /> 
     <set name="Aug" value="622" color="588526" /> 
     <set name="Sep" value="376" color="B3AA00" /> 
     <set name="Oct" value="494" color="008ED6" /> 
     <set name="Nov" value="761" color="9D080D" /> 
     <set name="Dec" value="960" color="A186BE" /> 
     <trendlines>
         <line startValue="700" color="91c728" displayValue="AVG" showOnTop="1" /> 
     </trendlines>
</graph>

 

   这个是FusionCharts，一个图型报表js，现在的要求就是从数据库读数据，生成XML然后供此JS读取生成图表

 

  现在好像只有一个办法，就是读-->string-->append--write(XML),目前我只发现这一种方法，不知道大家还好什么好的方法没有？

 

 或者是有没有更好的报表JS，供我参考下，但这次的重点还是怎么用java生成不是很规则的XML

 

Answer 1

如果是数据库里出来的，我猜应该有持有化bean结构吧

比如定义这种bean结构

[code="java"]package org.chart.xml.bean;

import java.util.ArrayList;
import java.util.List;

import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

/**

• 最顶层GraphTag
  */
  @XmlRootElement(name="graph")
  public class GraphBean {

  private String caption;
  private String xAxisName;
  private String yAxisName;
  private int decimalPrecision;
  private int formatNumberScale;
  private List detailList = new ArrayList();
  private TrendLinesBean trendLines;

  @XmlAttribute
  public String getCaption() {
  return caption;
  }
  public void setCaption(String caption) {
  this.caption = caption;
  }

  @XmlAttribute
  public String getxAxisName() {
  return xAxisName;
  }
  public void setxAxisName(String xAxisName) {
  this.xAxisName = xAxisName;
  }

  @XmlAttribute
  public String getyAxisName() {
  return yAxisName;
  }
  public void setyAxisName(String yAxisName) {
  this.yAxisName = yAxisName;
  }

  @XmlAttribute
  public int getDecimalPrecision() {
  return decimalPrecision;
  }
  public void setDecimalPrecision(int decimalPrecision) {
  this.decimalPrecision = decimalPrecision;
  }

  @XmlAttribute
  public int getFormatNumberScale() {
  return formatNumberScale;
  }
  public void setFormatNumberScale(int formatNumberScale) {
  this.formatNumberScale = formatNumberScale;
  }

  @XmlElement(name="set")
  public List getDetailList() {
  return detailList;
  }
  public void setDetailList(List detailList) {
  this.detailList = detailList;
  }

  @XmlElement(name="trendlines")
  public TrendLinesBean getTrendLines() {
  return trendLines;
  }
  public void setTrendLines(TrendLinesBean trendLines) {
  this.trendLines = trendLines;
  }

  /**

  • 增加一个Set标签 */ public void addDetail(DetailInfoBean bean) { this.detailList.add(bean); }

}[/code]

[code="java"]package org.chart.xml.bean;

import javax.xml.bind.annotation.XmlAttribute;

/**

• Set标签内容
  */
  public class DetailInfoBean {

  private String name;

  private String value;

  private String color;

  private String hoverText;

  @XmlAttribute
  public String getName() {
  return name;
  }

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

  @XmlAttribute
  public String getValue() {
  return value;
  }

  public void setValue(String value) {
  this.value = value;
  }

  @XmlAttribute
  public String getColor() {
  return color;
  }

  public void setColor(String color) {
  this.color = color;
  }

  @XmlAttribute
  public String getHoverText() {
  return hoverText;
  }

  public void setHoverText(String hoverText) {
  this.hoverText = hoverText;
  }
  }[/code]

[code="java"]package org.chart.xml.bean;

import java.util.ArrayList;
import java.util.List;

import javax.xml.bind.annotation.XmlElement;

/**

• TreadLines标签内容
  */
  public class TrendLinesBean {
  private List lineList = new ArrayList();

  @XmlElement(name="line")
  public List getLineList() {
  return lineList;
  }

  public void setLineList(List lineList) {
  this.lineList = lineList;
  }

  public void addLine(LineBean bean) {
  this.lineList.add(bean);
  }
  }[/code]

[code="java"]package org.chart.xml.bean;

import javax.xml.bind.annotation.XmlAttribute;

/**

• Line标签内容
  */
  public class LineBean {
  private String startValue;
  private String color;
  private String displayValue;
  private String showOnTop;

  @XmlAttribute
  public String getStartValue() {
  return startValue;
  }
  public void setStartValue(String startValue) {
  this.startValue = startValue;
  }

  @XmlAttribute
  public String getColor() {
  return color;
  }
  public void setColor(String color) {
  this.color = color;
  }

  @XmlAttribute
  public String getDisplayValue() {
  return displayValue;
  }
  public void setDisplayValue(String displayValue) {
  this.displayValue = displayValue;
  }

  @XmlAttribute
  public String getShowOnTop() {
  return showOnTop;
  }
  public void setShowOnTop(String showOnTop) {
  this.showOnTop = showOnTop;
  }

}[/code]

以上4个bean均为pojo。一般支持ORM的框架都会返回这种形式的数据结构。

接下来测试类:
[code="java"]package org.chart.xml.bean;

import java.io.PrintWriter;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;

public class Test {

/**
 * 测试
 */
private Test() throws JAXBException {

    // 模拟ORM从DB中出数据
    GraphBean graphBean = initGraphTag();

    addDetail(graphBean, "Jan", "462", "AFD8F8", "Janssss.xxx");
    addDetail(graphBean, "Feb", "857", "F6BD0F");
    addDetail(graphBean, "Mar", "671", "8BBA00");
    addDetail(graphBean, "Apr", "494", "FF8E46");
    addDetail(graphBean, "May", "761", "008E8E");
    addDetail(graphBean, "Jun", "960", "D64646");
    addDetail(graphBean, "Jul", "629", "8E468E");
    addDetail(graphBean, "Aug", "622", "588526");
    addDetail(graphBean, "Sep", "376", "B3AA00");
    addDetail(graphBean, "Oct", "494", "008ED6");
    addDetail(graphBean, "Nov", "761", "9D080D");
    addDetail(graphBean, "Dec", "960", "A186BE");

    addTrendlines(graphBean);

    // 生成XML
    printXml(graphBean);
}

private GraphBean initGraphTag() {
    GraphBean graphBean = new GraphBean();
    graphBean.setCaption("Monthly Unit Sales");
    graphBean.setxAxisName("Month");
    graphBean.setyAxisName("Units");
    graphBean.setDecimalPrecision(0);
    graphBean.setFormatNumberScale(0);
    return graphBean;
}

private void addDetail(GraphBean graphBean, String... args) {
    DetailInfoBean detailInfo = new DetailInfoBean();

    if (args.length > 0) {
        detailInfo.setName(args[0]);
    }

    if (args.length > 1) {
        detailInfo.setValue(args[1]);
    }

    if (args.length > 2) {
        detailInfo.setColor(args[2]);
    }

    if (args.length > 3) {
        detailInfo.setHoverText(args[3]);
    }
    graphBean.addDetail(detailInfo);
}

private void addTrendlines(GraphBean graphBean) {

    TrendLinesBean trendLines = new TrendLinesBean();

    addLine(trendLines, "700", "91c728", "AVG", "1");

    graphBean.setTrendLines(trendLines);

}

private void addLine(TrendLinesBean trendLines, String... args) {

    LineBean line = new LineBean();

    if (args.length > 0) {
        line.setStartValue(args[0]);
    }

    if (args.length > 1) {
        line.setColor(args[1]);
    }

    if (args.length > 2) {
        line.setDisplayValue(args[2]);
    }

    if (args.length > 3) {
        line.setShowOnTop(args[3]);
    }
    trendLines.addLine(line);
}

private void printXml(GraphBean graphBean) throws JAXBException {

    JAXBContext context = JAXBContext.newInstance(GraphBean.class);
    Marshaller marshaller = context.createMarshaller();

    // 生成文件的话请将这里的System.out替换成FileOutputStream或者直接文件path
    PrintWriter writer = new PrintWriter(System.out);
    marshaller.marshal(graphBean, writer);
    writer.close();
}

/**
 * @param args
 * @throws JAXBException 
 */
public static void main(String[] args) throws JAXBException {
    new Test();
}

}

[/code]

在控制台看结果就可以看到你的xml了

这招叫jaxb2。是jdk6新增的方法，也是最快的方法，同时也是离OO和pojo最接近的方法。只需在javabean中配置annotation即可实现。一次配置永远可用