关于struts2的checkboxlist、select等标签发生could not be resolved as a collection/array/map/enumeration/iterator type异常的记录
1 刚进入该界面的时候发生错误，原因是 list="roles"中的这个集合是空的，导致错误
解决办法很简单，不能让list为空
2
刚进入该界面的时候list是有数据的，当点击提交等按钮的时候，数据被提交到后台,如果配置了验证框架或者在action中写了validate方法，校验没有通过，未走action，直接返回了input，又指定回了当前界面。
此时的checkboxlist中的list丢失了，导致了如上错误（这个错误提示的不太友好，让人认为是类转换错误）
解决办法是把初始化list的工作放到prepare拦截器中，因为prepare是在validate拦截器之前执行，即实现prepareble接口：
publicclass RoleAction extends ActionSupport implements Preparable{
@Override
publicvoid prepare() throws Exception {
//初始化list
}
}
意思就是你这个类实现接口Preparable里的prepare，把原先获取list放入到prepare()方法中，然后在原先List语句上调用这个方法就OK
package com.ccse.frame.action.rule;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.annotation.Resource;
import com.ccse.core.SeqManager;
import com.ccse.core.command.QueryFilter;
import com.ccse.core.command.sql.SqlQueryFilter;
import com.ccse.core.command.sql.SqlSpellerDbType;
import com.ccse.core.util.BeanUtil;
import com.ccse.core.web.action.BaseAction;
import com.ccse.frame.model.base.BaseUser;
import com.ccse.frame.model.rule.RuleAutogeneration;
import com.ccse.frame.service.rule.RuleAutogenerationService;
import com.ccse.oa.util.ContextUtil;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import com.opensymphony.xwork2.Preparable;
/**
* 证书自动生成规则
*
* @author hackermi
* @date 2013-7-3 下午02:33:30
*/
public class RuleAutogenerationAction extends BaseAction implements Preparable{
/**
*
*/
private static final long serialVersionUID = 1L;
@Resource
private RuleAutogenerationService ruleAutogenerationService;
private RuleAutogeneration ruleAutogeneration;
private String ruleId;
//创建新版本
private boolean ruleRoot = false;
public boolean getRuleRoot() {
return ruleRoot;
}
public void setRuleRoot(boolean ruleRoot) {
this.ruleRoot = ruleRoot;
}
public String getRuleId() {
return ruleId;
}
public void setRuleId(String ruleId) {
this.ruleId = ruleId;
}
public RuleAutogeneration getRuleAutogeneration() {
return ruleAutogeneration;
}
public void setRuleAutogeneration(RuleAutogeneration ruleAutogeneration) {
this.ruleAutogeneration = ruleAutogeneration;
}
/**
* 显示列表
*/
public String list() {
QueryFilter filter = new QueryFilter(getReq());
List<RuleAutogeneration> list = ruleAutogenerationService
.getAll(filter);
Type type = new TypeToken<List<RuleAutogeneration>>() {
}.getType();
StringBuffer buff = new StringBuffer("{\"total\":").append(
filter.getPagingBean().getTotalItems()).append(",\"rows\":");
Gson gson = new Gson();
buff.append(gson.toJson(list, type));
buff.append("}");
jsonString = buff.toString();
return SUCCESS;
}
/**
* 批量删除
*
* @return
*/
public String multiDel() {
String ids = getReq().getParameter("ids");
if (ids != null) {
for (String id : ids.split(",")) {
ruleAutogenerationService.remove(id);
}
}
jsonString = "{success:true}";
return SUCCESS;
}
public void prepare() throws Exception {
// TODO Auto-generated method stub
List sysTypes=ruleAutogenerationService.getsysType();//所属类型
List sysType=new ArrayList();
for (int i = 0; i < sysTypes.size(); i++) {
System.out.println(sysTypes.get(i));
}
Iterator<?> itr = sysTypes.iterator();
while (itr.hasNext()) {
Map<?, ?> nextObj = (Map<?, ?>) itr.next();
String value=(String) nextObj.get("ywcode");
sysType.add(value.trim());
// sysType.add((String)nextObj.get("ywcode"));
}
this.getRequest().put("sysType", sysType);
}
/**
* 新增SAMIS
*
* @return
*/
public String getSAMIS() {
try {
// List sourCeNames=ruleAutogenerationService.getSourCeName();
// this.getRequest().put("sourcenames", sourCeNames);//系统类型
String ruleRoot = this.getReq().getParameter("ruleRoot");// 是否是创建新版本
if (ruleId != null && !"".equals(ruleId)) {
ruleAutogeneration = ruleAutogenerationService.get(ruleId);
if (ruleRoot != null && !"".equals(ruleRoot)) {
ruleAutogeneration.setRuleRoot(ruleRoot);
this.getReq().setAttribute("ruleRoot", ruleRoot);
}
}
this.prepare();
this.setForwardPage("/pages/rule/RuleAutogenerationSAMISForm.jsp");
jsonString = null;
return SUCCESS;
} catch (Exception e) {
e.printStackTrace();
return this.err(e);
}
}
/**
* 新增SSMIS
*
* @return
*/
public String getSSMIS() {
try {
//List sourCeNames=ruleAutogenerationService.getSourCeName();
// this.getRequest().put("sourcenames", sourCeNames);//所属系统
String ruleRoot = this.getReq().getParameter("ruleRoot");// 是否是创建新版本
if (ruleId != null && !"".equals(ruleId)) {
ruleAutogeneration = ruleAutogenerationService.get(ruleId);
if (ruleRoot != null && !"".equals(ruleRoot)) {
ruleAutogeneration.setRuleRoot(ruleRoot);
this.getReq().setAttribute("ruleRoot", ruleRoot);
}
}
this.setForwardPage("/pages/rule/RuleAutogenerationSSMISForm.jsp");
jsonString = null;
return SUCCESS;
} catch (Exception e) {
e.printStackTrace();
return this.err(e);
}
}
/**
* 添加及保存操作
*/
public String save() {
try {
BaseUser baseUser = ContextUtil.getCurrentUser();
//新增
if (ruleAutogeneration.getRuleId() == null || "".equals(ruleAutogeneration.getRuleId())) {
ruleAutogeneration.setRuleId(null);
ruleAutogeneration.setRuleVersion("1.0");
ruleAutogeneration.setRuleRoot(SeqManager.getSeqMang().getUUID());//根节点
ruleAutogeneration.setLastUpdateTime(new Date());// 修改时间
ruleAutogeneration.setCreTime(new Date());// 创建时间
ruleAutogeneration.setCreUserId(baseUser.getId());// 创建人ID
ruleAutogeneration.setCreUserName(baseUser.getUsername());// 创建人姓名
ruleAutogenerationService.save(ruleAutogeneration);
} else {
RuleAutogeneration orgRuleAutogeneration = ruleAutogenerationService.get(ruleAutogeneration.getRuleId());
if(null != orgRuleAutogeneration) {
BeanUtil.copyNotNullProperties(orgRuleAutogeneration, ruleAutogeneration);
//创建新版本
if (ruleRoot) {
ruleAutogenerationService.evict(orgRuleAutogeneration);//清空旧对象的缓存
orgRuleAutogeneration.setRuleId(null);
orgRuleAutogeneration.setRuleVersion(ruleAutogenerationService.getBigVersion(orgRuleAutogeneration));
orgRuleAutogeneration.setLastUpdateTime(new Date());//修改时间
orgRuleAutogeneration.setCreTime(new Date());//创建时间
orgRuleAutogeneration.setCreUserName(baseUser.getUsername());
ruleAutogenerationService.save(orgRuleAutogeneration);
} else {
//修改
orgRuleAutogeneration.setLastUpdateTime(new Date());// 修改时间
orgRuleAutogeneration.setUpdateUserId(baseUser.getId());//修改创建人ID
orgRuleAutogeneration.setUpdateUserName(baseUser.getUsername());// 修改人姓名
ruleAutogenerationService.save(orgRuleAutogeneration);
}
}else{
throw new RuntimeException("对象不存在");
}
}
} catch (Exception ex) {
logger.error(ex.getMessage());
ex.printStackTrace();
}
setJsonString("{success:true}");
if (ruleAutogeneration.getSysId().equals("SAMIS")) {
this.setForwardPage("/pages/rule/RuleAutogenerationSAMISForm.jsp");
} else if (ruleAutogeneration.getSysId().equals("SSMIS")) {
this.setForwardPage("/pages/rule/RuleAutogenerationSSMISForm.jsp");
}
return SUCCESS;
}
}
