com.washingtonpost.mongo.dropwizard.MongoFactory Maven / Gradle / Ivy
package com.washingtonpost.mongo.dropwizard;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.Preconditions;
import com.mongodb.DB;
import com.mongodb.Mongo;
import com.mongodb.MongoClient;
import com.mongodb.MongoClientURI;
import com.washingtonpost.mongo.dropwizard.exceptions.NullDBNameException;
import java.net.UnknownHostException;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.builder.ToStringBuilder;
/**
* An object of this class creates a single instance of the MongoClient object.
*
* To use this class add it as a field with getters and setters to your Configuration class and call the buildClient
* method in your applications run method. The resulting MongoClient can then be passed to your Resources.
*
* An example of the yaml configuration:
*
* mongoClient:
* user: yourUser
* pass: yourPassword
* hosts: localhost:27017,192.168.1.12:27017
* dbName: foo
*
*/
public class MongoFactory {
/**
* Optional Username used to connect; if provided with a non-null password, an attempt to authenticate
* to the provided {@code dbName} will be made.
*/
@JsonProperty
private String user;
/**
* Optional Password associated with the user; if provided with a non-null user, an attempt to authenticate
* to the provided {@code dbName} will be made.
*/
@JsonProperty
private String pass;
/**
* At least one, but possibly many comma-separated (server:port) pairs to which the user/pass should connect
* See http://docs.mongodb.org/manual/reference/connection-string/
*/
@JsonProperty
private String hosts;
/**
* Optional name of the database. This property is required to use the dbBuild method.
*/
@JsonProperty
private String dbName;
/**
* Optional "?options" string to append to the end of the connection URI.
* See http://docs.mongodb.org/manual/reference/connection-string/
*/
@JsonProperty
private String options;
/**
* Optional flag that prevents any actual connections to the Mongo DB
*/
@JsonProperty
private boolean disabled;
/**
* The mongo API documentation for
* MongoClient states that there should only be one object per JVM, so this property is only set once.
*/
private MongoClient mongoClient;
public String getUser() {
return this.user;
}
public void setUser(String user) {
this.user = user;
}
public String getPass() {
return this.pass;
}
public void setPass(String pass) {
this.pass = pass;
}
public String getHosts() {
return this.hosts;
}
public void setHosts(String hosts) {
this.hosts = hosts;
}
public String getOptions() {
return this.options;
}
public void setOptions(String options) {
this.options = options;
}
public String getDbName() {
return dbName;
}
public void setDbName(String dbName) {
this.dbName = dbName;
}
public boolean isDisabled() {
return disabled;
}
public void setDisabled(boolean disabled) {
this.disabled = disabled;
this.dbName = "foo"; // to avoid an NPE when guice calls "buildDB()"... it doesn't matter what this is
}
/**
* Builds the MongoClient from a set of connections specified in the configuration file.
* If both the {@code user} and {@code pass} are non-null and non-empty, the {@code MongoClient} that this
* method returns will attempt to authenticate against the Mongo DB.
* @return A Mongo API {@code MongoClient} object.
* @throws UnknownHostException Thrown if the server can not be found.
*/
public MongoClient buildClient() throws UnknownHostException {
if (this.disabled) {
return new MongoClient();
}
if (this.mongoClient != null) {
return mongoClient;
}
this.mongoClient = new MongoClient(buildMongoClientURI());
return this.mongoClient;
}
/**
* Builds a Mongo {@code DB} object from connection and db info set in a configuration file.
* @return A Mongo Java API {@code DB} object.
* @throws java.net.UnknownHostException if the host is unknown
*/
public DB buildDB() throws UnknownHostException {
return buildDB(this.dbName);
}
/**
* Builds a Mongo {@code DB} object from connection and db info set in a configuration file, but against whatever DB is
* provided in the {@code dbName} argument.
* @param dbName The name of the mongo DB to connect to.
* @return A Mongo Java API {@code DB} object.
* @throws java.net.UnknownHostException if the host is unknown
*/
public DB buildDB(String dbName) throws UnknownHostException {
if (dbName == null && !this.disabled) {
throw new NullDBNameException();
}
Mongo client = buildClient();
return client.getDB(dbName);
}
// Visible for testing
MongoClientURI buildMongoClientURI() {
Preconditions.checkState((StringUtils.isEmpty(this.user) && StringUtils.isEmpty(this.pass))
|| (!StringUtils.isEmpty(this.user) && !StringUtils.isEmpty(this.pass)),
"If you define a Mongo user, you must also define a Mongo pass, and vice-versa");
Preconditions.checkNotNull(this.hosts, "Must define Mongo 'hosts' property");
StringBuilder uriString = new StringBuilder("mongodb://");
if (!StringUtils.isEmpty(this.user)) {
uriString.append(this.user)
.append(":")
.append(this.pass)
.append("@");
}
uriString.append(this.hosts);
if (!StringUtils.isEmpty(this.dbName)) {
uriString.append("/")
.append(this.dbName);
}
if (!StringUtils.isEmpty(this.options)) {
if (StringUtils.isEmpty(this.dbName)) {
// If we didn't slap a "/" at the end of the hosts because there's no DBName defined,
// we need to do that here before sticking the "?options" in the connection URI
uriString.append("/");
}
uriString.append("?")
.append(this.options);
}
return new MongoClientURI(uriString.toString());
}
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
}