How to use reflection to filter list objects in Java

Reflection has an impact on efficiency. Use with caution! ! !

1. Object structure

public class BusinessDept {
private String year;//年
private String month;//月
private String deptName;//部门名称
private String deptLeader;//部门负责人
private Double jyz; //经营值
private Double rev; //收入
private Double exp; //支出
private Double tWorkTime; //填报工时
private Double sWorkTime; //标准工时
private Double param; //经营参数

public void setYear(String year) {
this.year = year;
}

public void setMonth(String month) {
this.month = month;
}

public void setDeptName(String deptName) {
this.deptName = deptName;
}

public void setDeptLeader(String deptLeader) {
this.deptLeader = deptLeader;
}

public void setJyz(Double jyz) {
this.jyz = jyz;
}

public String getYear() {
return year;
}

public String getMonth() {
return month;
}

public String getDeptName() {
return deptName;
}

public String getDeptLeader() {
return deptLeader;
}

public Double getJyz() {
return jyz;
}

public Double getRev() {
return rev;
}

public Double getExp() {
return exp;
}

public Double gettWorkTime() {
return tWorkTime;
}

public Double getsWorkTime() {
return sWorkTime;
}

public Double getParam() {
return param;
}

public void setRev(Double rev) {
this.rev = rev;
}

public void setExp(Double exp) {
this.exp = exp;
}

public void settWorkTime(Double tWorkTime) {
this.tWorkTime = tWorkTime;
}

public void setsWorkTime(Double sWorkTime) {
this.sWorkTime = sWorkTime;
}

public void setParam(Double param) {
this.param = param;
}

public <E> E get(String name) {
Class cl = this.getClass();

Field[] fields = cl.getDeclaredFields();
try {
for (Field field : fields) {
field.setAccessible(true);
if (field.getName().equals(name)) {
return (E) field.get(this);
}
}
} catch (IllegalAccessException e) {
e.printStackTrace();
}
return null;
}
}

2. Get value based on field name

public <E> E get(String name) {
Class cl = this.getClass();

Field[] fields = cl.getDeclaredFields();
try {
for (Field field : fields) {
field.setAccessible(true);
if (field.getName().equals(name)) {
return (E) field.get(this);
}
}
} catch (IllegalAccessException e) {
e.printStackTrace();
}
return null;
}

3. Filter list

List businessDeptList = this.myQuery();
//筛选符合条件的list
if (businessDeptList.size()>0){
businessDeptList = this.filterExact("year",year,businessDeptList);
businessDeptList = this.filterExact("month",month,businessDeptList);
businessDeptList = this.filterVague("deptName",deptName,businessDeptList);
businessDeptList = this.filterVague("deptLeader",deptLeader,businessDeptList);
if(!StringUtils.isEmpty(jyz)){
businessDeptList = this.filterExact("jyz",Double.parseDouble(jyz),businessDeptList);
}
if(!StringUtils.isEmpty(param)){
businessDeptList = this.filterExact("param",Double.parseDouble(param),businessDeptList);
}
if(!StringUtils.isEmpty(sWorkTime)){
businessDeptList = this.filterExact("sWorkTime",Double.parseDouble(sWorkTime),businessDeptList);
}
if(!StringUtils.isEmpty(rev)){
businessDeptList = this.filterExact("rev",Double.parseDouble(rev),businessDeptList);
}
if(!StringUtils.isEmpty(exp)){
businessDeptList = this.filterExact("exp",Double.parseDouble(exp),businessDeptList);
}
if(!StringUtils.isEmpty(tWorkTime)){
businessDeptList = this.filterExact("tWorkTime",Double.parseDouble(tWorkTime),businessDeptList);
}

}

4. Exact match

//精确匹配
private <T>List<BusinessDept> filterExact(String name,T t,List<BusinessDept> businessDepts){
if(t.toString().isEmpty()){
return businessDepts;
}
List<BusinessDept> list = new ArrayList<BusinessDept>();
if(businessDepts.size()>0){
for(int i = 0;i<businessDepts.size();i++){
if(businessDepts.get(i).get(name).equals(t)){
list.add(businessDepts.get(i));
}
}
}
return list;
}

5. Fuzzy matching

//模糊匹配
private List<BusinessDept> filterVague(String name,String s,List<BusinessDept> businessDepts){
if(s.isEmpty()){
return businessDepts;
}
List<BusinessDept> list = new ArrayList<BusinessDept>();
if(businessDepts.size()>0){
for(int i = 0;i<businessDepts.size();i++){
if(businessDepts.get(i).get(name).toString().contains(s)){
list.add(businessDepts.get(i));
}
}
}
return list;
}

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