Metode complicated equals().
Kanggo gampang ngleksanakake cara equals , sampeyan bisa nggunakake kelas EqualsBuilder . Ing ngisor iki sawetara conto kanggo nuduhake cara kerjane.
Nyetel kolom khusus kanggo mbandhingake:
public class User {
private String name;
private String email;
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (!(o instanceof User user)) return false;
return new EqualsBuilder().append(name, user.name).append(email, user.email).isEquals();
}
}
Uga, kelas iki bisa mbandhingake obyek liwat refleksi:
@Override
public boolean equals(Object obj) {
return EqualsBuilder.reflectionEquals(this, obj);
}
Metode hashCode() rumit
Kanggo ngleksanakake metode hashCode , sampeyan kudu nggunakake kelas HashCodeBuilder .
Pilihan lapangan:
@Override
public int hashCode() {
return new HashCodeBuilder(17, 37)
.append(name)
.append(email)
.toHashCode();
}
Nggunakake refleksi kanggo mbangun kode hash:
@Override
public int hashCode() {
return HashCodeBuilder.reflectionHashCode(this);
}
We use reflection and ignore certain fields:
@Override
public int hashCode() {
return HashCodeBuilder.reflectionHashCode(this, "name");
}
Metode toString() rumit
Kanthi cara sing padha, sampeyan bisa uga ngetrapake metode toString () . Maneh, kita nggunakake kelas ToStringBuilder .
Kothak kasebut disetel kaya ing rong kasus sadurunge:
@Override
public String toString() {
return new ToStringBuilder(this)
.append(name)
.append(email)
.toString();
}
Tuladha asil:
org.example.User@4b67cf4d[name=John,email=email@email.com]
Sampeyan uga bisa nemtokake jeneng lapangan kanthi eksplisit:
@Override
public String toString() {
return new ToStringBuilder(this)
.append("nameUser", name)
.append("emailUser", email)
.toString();
}
Tuladha asil:
org.example.User@4b67cf4d[nameUser=John,emailUser=email@email.com]
Sampeyan bisa ngganti gaya teks nggunakake setelan:
@Override
public String toString() {
return new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE)
.append(name)
.append(email)
.toString();
}
Tuladha asil:
User[John,emailUser=email@email.com]
Ana sawetara gaya kaya JSON, ora ana Classname, cendhak lan liya-liyane.
Nggunakake refleksi:
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
Nggunakake refleksi lan nemtokake gaya tartamtu:
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this, ToStringStyle.SHORT_PREFIX_STYLE);
}