问题描述
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
解决方案
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<DetailInfoBean> detailList = new ArrayList<DetailInfoBean>();private TrendLinesBean trendLines;@XmlAttributepublic String getCaption() {return caption;}public void setCaption(String caption) {this.caption = caption;}@XmlAttributepublic String getxAxisName() {return xAxisName;}public void setxAxisName(String xAxisName) {this.xAxisName = xAxisName;}@XmlAttributepublic String getyAxisName() {return yAxisName;}public void setyAxisName(String yAxisName) {this.yAxisName = yAxisName;}@XmlAttributepublic int getDecimalPrecision() {return decimalPrecision;}public void setDecimalPrecision(int decimalPrecision) {this.decimalPrecision = decimalPrecision;}@XmlAttributepublic int getFormatNumberScale() {return formatNumberScale;}public void setFormatNumberScale(int formatNumberScale) {this.formatNumberScale = formatNumberScale;}@XmlElement(name="set")public List<DetailInfoBean> getDetailList() {return detailList;}public void setDetailList(List<DetailInfoBean> 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);}}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;@XmlAttributepublic String getName() {return name;}public void setName(String name) {this.name = name;}@XmlAttributepublic String getValue() {return value;}public void setValue(String value) {this.value = value;}@XmlAttributepublic String getColor() {return color;}public void setColor(String color) {this.color = color;}@XmlAttributepublic String getHoverText() {return hoverText;}public void setHoverText(String hoverText) {this.hoverText = hoverText;}}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<LineBean> lineList = new ArrayList<LineBean>();@XmlElement(name="line")public List<LineBean> getLineList() {return lineList;}public void setLineList(List<LineBean> lineList) {this.lineList = lineList;}public void addLine(LineBean bean) {this.lineList.add(bean);}}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;@XmlAttributepublic String getStartValue() {return startValue;}public void setStartValue(String startValue) {this.startValue = startValue;}@XmlAttributepublic String getColor() {return color;}public void setColor(String color) {this.color = color;}@XmlAttributepublic String getDisplayValue() {return displayValue;}public void setDisplayValue(String displayValue) {this.displayValue = displayValue;}@XmlAttributepublic String getShowOnTop() {return showOnTop;}public void setShowOnTop(String showOnTop) {this.showOnTop = showOnTop;}}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: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XMLprintXml(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pathPrintWriter 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();}}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
解决方案二：
不是很规则的XML文件 ？上面的 xml 内容也是一个规则的 xml，与 xml 相关的标准有很多，形式有多样。 /** * 生成 xml 内容 */ public String generate() { ByteArrayOutputStream bos = null; try { bos = new ByteArrayOutputStream(1024); // 新建 format 用来格式化 xml 文件 OutputFormat format = OutputFormat.createPrettyPrint(); format.setEncoding("utf-8"); // 编码格式 format.setIndentSize(4); // Tab 缩进 XMLWriter writer = new XMLWriter(bos, format); Document document = DocumentHelper.createDocument(); // 创建文档 Element graph = document.addElement("graph"); // 创建根节点 graph.addAttribute("caption", "Monthly Unit Sales"); // add set Element node = graph.addElement("set"); node.addAttribute("name", "Jan"); node.addAttribute("value", "462"); // add trendlines node = graph.addElement("trendlines"); // add line node = node.addElement("line"); node.addAttribute("startValue", "700"); node.addAttribute("color", "91c728"); writer.write(document); writer.flush(); writer.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException ioe) { } return bos.toString(); }输出内容：<?xml version="1.0" encoding="utf-8"?><graph caption="Monthly Unit Sales"> <set name="Jan" value="462"/> <trendlines> <line startValue="700" color="91c728"/> </trendlines></graph>
解决方案三：
使用dom4j啊只要是标准xml就可以生成