我有一个构建器类,如下所示:
public final class RequestKey {
private final Long userid;
private final String deviceid;
private final String flowid;
private final int clientid;
private final long timeout;
private final boolean abcFlag;
private final boolean defFlag;
private final Map<String, String> baseMap;
private RequestKey(Builder builder) {
this.userid = builder.userid;
this.deviceid = builder.deviceid;
this.flowid = builder.flowid;
this.clientid = builder.clientid;
this.abcFlag = builder.abcFlag;
this.defFlag = builder.defFlag;
this.baseMap = builder.baseMap.build();
this.timeout = builder.timeout;
}
public static class Builder {
protected final int clientid;
protected Long userid = null;
protected String deviceid = null;
protected String flowid = null;
protected long timeout = 200L;
protected boolean abcFlag = false;
protected boolean defFlag = true;
protected ImmutableMap.Builder<String, String> baseMap = ImmutableMap.builder();
public Builder(int clientid) {
checkArgument(clientid > 0, "clientid must not be negative or zero");
this.clientid = clientid;
}
public Builder setUserId(long userid) {
checkArgument(userid > 0, "userid must not be negative or zero");
this.userid = Long.valueOf(userid);
return this;
}
public Builder setDeviceId(String deviceid) {
checkNotNull(deviceid, "deviceid cannot be null");
checkArgument(deviceid.length() > 0, "deviceid can't be an empty string");
this.deviceid = deviceid;
return this;
}
public Builder setFlowId(String flowid) {
checkNotNull(flowid, "flowid cannot be null");
checkArgument(flowid.length() > 0, "flowid can't be an empty string");
this.flowid = flowid;
return this;
}
public Builder baseMap(Map<String, String> baseMap) {
checkNotNull(baseMap, "baseMap cannot be null");
this.baseMap.putAll(baseMap);
return this;
}
public Builder abcFlag(boolean abcFlag) {
this.abcFlag = abcFlag;
return this;
}
public Builder defFlag(boolean defFlag) {
this.defFlag = defFlag;
return this;
}
public Builder setTimeout(long timeout) {
checkArgument(timeout > 0, "timeout must not be negative or zero");
this.timeout = timeout;
return this;
}
public RequestKey build() {
if (!this.isValid()) {
throw new IllegalStateException("You have to pass at least one"
+ " of the following: userid, flowid or deviceid");
}
return new RequestKey(this);
}
private boolean isValid() {
return !(TestUtils.isEmpty(userid) && TestUtils.isEmpty(flowid) && TestUtils.isEmpty(deviceid));
}
}
// getters here
}
我正在制作这样的构建器类:
Map<String, String> holder = new HashMap<String, String>();
holder.put("abc", "hello");
RequestKey keys = new RequestKey.Builder(310).setUserId(75076L).baseMap(holder).setTimeout(10000L).build();
现在,我想制作keys
个对象的副本并将其分配给新的RequestKey
对象,并将其keysCopy
更改为keysCopy
并更改中的用户ID变量到其他一些用户ID说12345L
。我怎么能这样做?
在我的其他类中,我可以访问此keys
对象,因此我想将其复制到keysCopy
对象,然后修改用户ID以使其中包含12345L
,有时我可能会需要通过调用此setter FlowId
来设置setFlowId
。
答案 0 :(得分:2)
实现目标的一种方法是创建一个Builder
构造函数,该构造函数接受RequestKey
个对象并将Builder
的成员变量初始化为RequestKey
的成员变量。 },然后只需修改你需要的字段。
public Builder(RequestKey key) {
this.userid = key.userid;
this.deviceid = key.deviceid;
this.baseMap = ImmutableMap.<String,String>builder().putAll( key.baseMap );
...
}
RequestKey keys = ...;
RequestKey keysCopy = new RequestKey.Builder( keys ).setUserId( 12345L ).build();