/*下面是从poi导出EXCEL的一部分代码,主要将传参数的list转换为map类型,list装载的数据是从数据库取出来的,可以是数组类型,也可以是map类型,也可以是实体类*/
public static TableData createTableData(List list,TableHeaderMetaData headMeta,String[] fields){
TableData td = new TableData(headMeta);
TableDataRow row = null;
if(list != null && list.size()>0){
if(list.get(0).getClass().isArray()){//list为数组类型
for (Object obj : list){
row = new TableDataRow(td);
for(Object o : (Object[])obj){
row.addCell(o);
}
td.addRow(row);
}
}else{//JavaBean或Map类型
for (Object obj : list){
row = new TableDataRow(td);
//判断是//JavaBean(实体类)还是Map类型 ,如果是javaBean将调用 obj:beanToMap,转为map类型
Map<String, Object> map = (obj instanceof Map)?(Map<String, Object>)obj:beanToMap(obj);
for(String key : fields){
row.addCell(map.get(key));
}
td.addRow(row);
}
}
}
return td;
}
//将javabean转为map类型,然后返回一个map类型的值
public static Map<String, Object> beanToMap(Object obj) {
Map<String, Object> params = new HashMap<String, Object>(0);
try {
PropertyUtilsBean propertyUtilsBean = new PropertyUtilsBean();
PropertyDescriptor[] descriptors = propertyUtilsBean.getPropertyDescriptors(obj);
for (int i = 0; i < descriptors.length; i++) {
String name = descriptors[i].getName();
if (!StringUtils.equals(name, "class")) {
params.put(name, propertyUtilsBean.getNestedProperty(obj, name));
}
}
} catch (Exception e) {
e.printStackTrace();
}
return params;
}
放入上面方法的类需要 import java.beans.PropertyDescriptor;
需要引用两个jar包:commons-beanutils-1.9.2.jar commons-logging-1.2.jar
获取上面两个jar的网址分别是:http://commons.apache.org/beanutils http://commons.apache.org/proper/commons-logging/
注意:
如果只引用了commons-beanutils-1.9.2.jar 未引用 commons-beanutils-1.9.2.jar,控制台会报以下错误:
Exception in thread "main" java.lang.NoClassDefFoundError:org/apache/commons/logging/LogFactory
at org.apache.commons.beanutils.ConvertUtilsBean.<init>(ConvertUtilsBean.java:157)
at org.apache.commons.beanutils.BeanUtilsBean.<init>(BeanUtilsBean.java:117)
at org.apache.commons.beanutils.BeanUtilsBean$1.initialValue(BeanUtilsBean.java:68)
at org.apache.commons.beanutils.ContextClassLoaderLocal.get(ContextClassLoaderLocal.java:153)
at org.apache.commons.beanutils.BeanUtilsBean.getInstance(BeanUtilsBean.java:80)
at org.apache.commons.beanutils.BeanUtils.getProperty(BeanUtils.java:382)
at fighting.IntroSpectorDemo.main(IntroSpectorDemo.java:31)