I don't know of any java samples for loading tables from Google Cloud Storage into BigQuery. That said, if you follow the instructions for running query jobs here, you can run a Load job instead with the folowing:
Job job = new Job();
JobConfiguration config = new JobConfiguration();
JobConfigurationLoad loadConfig = new JobConfigurationLoad();
config.setLoad(loadConfig);
job.setConfiguration(config);
// Set where you are importing from (i.e. the Google Cloud Storage paths).
List<String> sources = new ArrayList<String>();
sources.add("gs://bucket/csv_to_load.csv");
loadConfig.setSourceUris(sources);
// Describe the resulting table you are importing to:
TableReference tableRef = new TableReference();
tableRef.setDatasetId("myDataset");
tableRef.setTableId("myTable");
tableRef.setProjectId(projectId);
loadConfig.setDestinationTable(tableRef);
List<TableFieldSchema> fields = new ArrayList<TableFieldSchema>();
TableFieldSchema fieldFoo = new TableFieldSchema();
fieldFoo.setName("foo");
fieldFoo.setType("string");
TableFieldSchema fieldBar = new TableFieldSchema();
fieldBar.setName("bar");
fieldBar.setType("integer");
fields.add(fieldFoo);
fields.add(fieldBar);
TableSchema schema = new TableSchema();
schema.setFields(fields);
loadConfig.setSchema(schema);
// Also set custom delimiter or header rows to skip here....
// [not shown].
Insert insert = bigquery.jobs().insert(projectId, job);
insert.setProjectId(projectId);
JobReference jobRef = insert.execute().getJobReference();
// ... see rest of codelab for waiting for job to complete.
For more information on the load configuration object, see the javadoc here.