Validate maxLifetime & idleTimeout and document their zero values.

vertx-sql-client/src/main/java/io/vertx/sqlclient/PoolOptions.java

@@ -188,12 +188,13 @@ public int getIdleTimeout() {
   }
 
   /**
-   * Establish an idle timeout for pooled connections.
+   * Establish an idle timeout for pooled connections, a value of zero disables the idle timeout.
    *
    * @param idleTimeout the pool connection idle timeout
    * @return a reference to this, so the API can be used fluently
    */
   public PoolOptions setIdleTimeout(int idleTimeout) {
+    Arguments.require(idleTimeout >= 0, "idleTimeout must be >= 0");
     this.idleTimeout = idleTimeout;
     return this;
   }
@@ -224,12 +225,13 @@ public int getMaxLifetime() {
   }
 
   /**
-   * Establish a max lifetime for pooled connections.
+   * Establish a max lifetime for pooled connections, a value of zero disables the maximum lifetime.
    *
    * @param maxLifetime the pool connection max lifetime
    * @return a reference to this, so the API can be used fluently
    */
   public PoolOptions setMaxLifetime(int maxLifetime) {
+    Arguments.require(maxLifetime >= 0, "maxLifetime must be >= 0");
     this.maxLifetime = maxLifetime;
     return this;
   }