设置多种数据类型,级联对象实例化,级联属性赋值
程序员文章站
2022-06-05 20:24:27
......
一个简单java类中的属性类型不仅仅只有string,还会包含有整数、浮点数、日期等,本课程主要讲解如何实现多种数据类型的赋值以及转换处理操作。 一个类可以与其它类发生引用关系,以描述彼此之间的关系,这样的级联结构中就需要考虑对象实例化问题,本课程主要讲解如何在多级vo配置关系时如何通过反射技术实现动态实例化对象操作。 类引用定义之后就会存在有其它引用类型的属性赋值操作,本课程主要讲解多级实例化对象属性内容的获取与其属性设置。
1 package com.twitter.demo; 2 3 import java.util.date; 4 import java.lang.reflect.field; 5 import java.lang.reflect.method; 6 import java.text.parseexception; 7 import java.text.simpledateformat; 8 9 class company{ 10 private string name; 11 private date createdate; 12 public string getname() { 13 return this.name; 14 } 15 public void setname(string name) { 16 this.name = name; 17 } 18 public date getcreatedate() { 19 return this.createdate; 20 } 21 public void setcreatedate(date createdate) { 22 this.createdate = createdate; 23 } 24 } 25 26 class dept{ 27 private string dname; 28 private string loc; 29 private company company; 30 public string getdname() { 31 return dname; 32 } 33 public void setdname(string dname) { 34 this.dname = dname; 35 } 36 public string getloc() { 37 return loc; 38 } 39 public void setloc(string loc) { 40 this.loc = loc; 41 } 42 public company getcompany() { 43 return company; 44 } 45 public void setcompany(company company) { 46 this.company = company; 47 } 48 } 49 50 class emp{ 51 private string ename; 52 private string job; 53 private double salary; 54 private integer age; 55 private date hiredate; 56 private dept dept; 57 public string getename() { 58 return ename; 59 } 60 public void setename(string ename) { 61 this.ename = ename; 62 } 63 public string getjob() { 64 return job; 65 } 66 public void setjob(string job) { 67 this.job = job; 68 } 69 public double getsalary() { 70 return salary; 71 } 72 public void setsalary(double salary) { 73 this.salary = salary; 74 } 75 public integer getage() { 76 return age; 77 } 78 public void setage(integer age) { 79 this.age = age; 80 } 81 public date gethiredate() { 82 return hiredate; 83 } 84 public void sethiredate(date hiredate) { 85 this.hiredate = hiredate; 86 } 87 public dept getdept() { 88 return dept; 89 } 90 public void setdept(dept dept) { 91 this.dept = dept; 92 } 93 } 94 95 class beanutils{ 96 private beanutils() {} 97 public static void setvalue(object obj,string value) { 98 string results[] = value.split("\\|"); 99 for(int x=0;x<results.length;x++) { 100 string attval[] = results[x].split(":"); 101 try { 102 if(attval[0].contains(".")) { 103 string temp[] = attval[0].split("\\."); 104 object currentobject = obj; 105 for(int y=0;y<temp.length-1;y++) { 106 method getmethod = currentobject.getclass().getdeclaredmethod("get" + stringutils.initcap(temp[y])); 107 object tempobject = getmethod.invoke(currentobject); 108 if(tempobject == null) { 109 field field = currentobject.getclass().getdeclaredfield(temp[y]); 110 method method = currentobject.getclass().getdeclaredmethod("set"+stringutils.initcap(temp[y]), field.gettype()); 111 object newobject = field.gettype().getdeclaredconstructor().newinstance(); 112 method.invoke(currentobject, newobject); 113 currentobject = newobject; 114 }else { 115 currentobject = tempobject; 116 } 117 } 118 }else { 119 field field = obj.getclass().getdeclaredfield(attval[0]); 120 method setmethod = obj.getclass().getdeclaredmethod("set"+stringutils.initcap(attval[0]), field.gettype()); 121 object convertvalue = beanutils.convertatributevalue(field.gettype().getname(), attval[1]); 122 setmethod.invoke(obj, convertvalue); 123 } 124 } catch (exception e) { 125 // todo: handle exception 126 } 127 } 128 } 129 130 private static object convertatributevalue(string type,string value) { 131 if("long".equals(type)||"java.lang.long".equals(type)) { 132 return long.parselong(value); 133 }else if ("int".equals(type)||"java.lang.integer".equals(type)) { 134 return integer.parseint(value); 135 }else if ("double".equals(type)||"java.lang.double".equals(type)) { 136 return double.parsedouble(value); 137 }else if ("java.util.date".equals(type)) { 138 simpledateformat sdf = null; 139 if(value.matches("\\d{4}-\\d{2}-\\d{2}")) { 140 sdf = new simpledateformat("yyyy-mm-dd"); 141 }else if (value.matches("\\d{4}-\\d{2}-\\d{2} \\d{2}-\\d{2}-\\d{2}")) { 142 sdf = new simpledateformat("yyyy-mm-dd hh:mm:ss"); 143 }else { 144 return new date(); 145 } 146 try { 147 return sdf.parse(type); 148 } catch (parseexception e) { 149 return new date(); 150 } 151 }else { 152 return value; 153 } 154 } 155 } 156 157 class stringutils{ 158 public static string initcap(string str) { 159 if(str == null || "".equals(str)) { 160 return str; 161 } 162 if(str.length() == 1) { 163 return str.touppercase(); 164 }else { 165 return str.substring(0,1).touppercase()+str.substring(1); 166 } 167 } 168 } 169 170 class classinstancefactory{ 171 private classinstancefactory() {} 172 public static <t> t create(class<?> clazz,string value) { 173 try { 174 object obj = clazz.getdeclaredconstructor().newinstance(); 175 beanutils.setvalue(obj, value); 176 return (t) obj; 177 } catch (exception e) { 178 return null; 179 } 180 181 } 182 } 183 184 public class javareflectdemo { 185 public static void main(string[] args) throws exception{ 186 string value = "ename:smith|job:clerk|salary:8960.00|age:30|hiredate:2003-10-03|" 187 +"dept.dname:财务部|dept.company.name:twitter|" 188 +"dept.company.createdate:2001-11-11"; 189 emp emp = classinstancefactory.create(emp.class, value); 190 system.out.println(emp); 191 system.out.println(emp.getdept()); 192 system.out.println(emp.getdept().getcompany()); 193 } 194 }
下一篇: 电影天堂爬虫