Java建立实体类医生字段有职业、兴趣等，实体类病人字段有年龄、疾病种类等

可以使用以下代码建立Java实体类Doctor和Patient：

// Doctor.java
public class Doctor {
    private String profession;
    private String interest;
    
    public Doctor(String profession, String interest) {
        this.profession = profession;
        this.interest = interest;
    }
    
    public String getProfession() {
        return profession;
    }
    
    public void setProfession(String profession) {
        this.profession = profession;
    }
    
    public String getInterest() {
        return interest;
    }
    
    public void setInterest(String interest) {
        this.interest = interest;
    }
}

// Patient.java
public class Patient {
    private int age;
    private String disease;
    
    public Patient(int age, String disease) {
        this.age = age;
        this.disease = disease;
    }
    
    public int getAge() {
        return age;
    }
    
    public void setAge(int age) {
        this.age = age;
    }
    
    public String getDisease() {
        return disease;
    }
    
    public void setDisease(String disease) {
        this.disease = disease;
    }
}

以上代码中，Doctor类有两个私有变量profession和interest，对应医生的职业和兴趣。Patient类有两个私有变量age和disease，对应病人的年龄和疾病种类。每个类都有一个构造函数和对应的getter和setter方法。在构造函数中，可以传入初始变量值并进行初始化。getter和setter方法用于获取和设置私有变量值。