我需要使用CSV中的数据更新表格。在更新发生之前验证所有数据：验证方法（未在下面给出）检查某些假设是否为真，并将对象“标记”为有效或无效。我已经对它进行了很多测试，它的工作正如我想的那样。
即便如此，我还是要保证即使批次出现故障也会执行所有陈述，这是我无法想到的。如果发生这种情况，我希望批处理这个失败语句将被跳过并且下一个被执行。
public void updateTable(List<PersonBean> personList) {
Connection connection = null;
PreparedStatement ps = null;
String updateDBPersonSQL = "UPDATE Person set merge_parent_id = ? WHERE id = ?";
try {
logger.info("DATA UPDATING STARTED");
input = new FileInputStream("resources/propertiesFiles/applications.properties");
properties.load(input);
final int batchSize = Integer.parseInt(properties.getProperty("batchSize"));
connection = DBConnection.getConnection();
connection.setAutoCommit(false);
int validObj = 0;
ps = connection.prepareStatement(updateDBPersonSQL);
for (int i = 0; i < personList.size(); i++) {
PersonBean person = personList.get(i);
if (person.getValidationStatus().equals("valid")) {
ps.setInt(1, person.getMerge_parent_id());
ps.setInt(2, person.getId());
ps.addBatch();
validObj++;
if (validObj % batchSize == 0 && validObj != 0) {
ps.executeBatch();
connection.commit();
logger.info((batchSize) + " rows updated");
}
}
}
int [] batchCount = ps.executeBatch();
connection.commit();
logger.info(batchCount.length + " rows updated");
writeValidationStatusToCSV(personList);
} catch (BatchUpdateException e) {
int [] updateCount = e.getUpdateCounts();
for (int i = 0; i < updateCount.length; i++) {
if (updateCount[i] >= 0) {
logger.info(updateCount.length + " objects updated.");
} else if (updateCount[i] == Statement.EXECUTE_FAILED) {
?????
}
}
logger.error(updateCount.length);
logger.error("BatchUpdateException: " + e);
logger.error("getNextException: " + e.getNextException());
try {
connection.rollback();
} catch (SQLException e1) {
logger.error("Rollback error: " + e1, e1);
}
} finally {
if (ps!= null) {
try {
ps.close();
} catch (SQLException e) {
logger.info(e);
}
}
}
logger.info("DATA UPDATING FINISHED");
}
我看到很多关于如何处理异常的材料，但没有人解释或指出了如何重试下一个语句的方向，这意味着，如何执行下一批。
我该如何设法做到这一点？
编辑：我正在使用Postgresql
答案 0 :(得分：0)
我设法通过使用try和catch语句包围批处理执行来重试下一批。通过这种方式，我可以抓住BatchUpdateException并调用continue语句。
try {
ps.executeBatch();
connection.commit();
/*Some more code*/
} catch (BatchUpdateException e) {
connection.rollback();
/*Some more code*/
continue;
}
我还使用了一些控制逻辑来标记＆＃34;已经执行并记录它们的语句和批处理，使得在某些语句失败时更容易进行故障排除。
以下是完整代码：
public void updateTable(List<PersonBean> personList) throws Exception {
logger.info("TABLE UPDATE STARTED");
List <PersonBean> personListValidated = createValidStmtList(personList);
Connection connection = null;
PreparedStatement ps = null;
String updatePersonSQL = "UPDATE Person SET merge_parent_id = ? WHERE id = ?";
input = new FileInputStream("resources/propertiesFiles/applications.properties");
properties.load(input);
final int batchSize = Integer.parseInt(properties.getProperty("batchSize"));
/*A list was used to "flag" the batches that were already executed. BatchStatus objs have only two parameters, number (incremented as the batches are being executed) and status (success or fail).*/
List <BatchStatus> batchStatusList = new ArrayList<BatchStatus>();
/*This variables will be used to help flag the batches and statements that were already executed.*/
int batchCount = 0;
int stmtAddedToBatchCount = 0;
try {
connection = DBConnection.getConnection();
connection.setAutoCommit(false);
ps = connection.prepareStatement(updatePersonSQL);
/*personListValidated contains the objects that will be updated in the table. Instead of doing the validation on the update method, I decomposed
* this part in other 2 methods, making it easier to control of the statements added to the batch.
*/
for (int i = 0; i < personListValidated.size(); i++) {
PersonBean personValid = personListValidated.get(i);
ps.setInt(1, personValid.getMerge_parent_id());
ps.setInt(2, personValid.getId());
ps.addBatch();
personValid.setToBatch("true");
stmtAddedToBatchCount++;
logger.info("Row added to batch (count: " + stmtAddedToBatchCount + ")");
if (stmtAddedToBatchCount % batchSize == 0) {
batchCount++;
try {
ps.executeBatch();
connection.commit();
for (int j = stmtAddedToBatchCount - batchSize; j < stmtAddedToBatchCount; j++){
personValid = personListValidated.get(j);
personValid.setValidationStatus("success");
}
BatchStatus batchStatusObj = new BatchStatus(batchCount, "sucess");
batchStatusList.add(batchStatusObj);
logger.info(batchStatusList.get(batchCount - 1));
} catch (BatchUpdateException e) {
connection.rollback();
for (int j = stmtAddedToBatchCount - batchSize; j < stmtAddedToBatchCount; j++){
personValid = personListValidated.get(j);
personValid.setValidationStatus("fail");
}
BatchStatus batchStatusObj = new BatchStatus(batchCount, "fail");
batchStatusList.add(batchStatusObj);
logger.info(batchStatusList.get(batchCount - 1));
logger.error("Bacth execution fail: " + e, e);
continue;
}
}
}
} catch (SQLException e) {
logger.error(e, e);
}
int[] lastBatchCount = null;
/*Try and catch to handle the statements executed on the last batch*/
try {
lastBatchCount = ps.executeBatch();
connection.commit();
for (int j = batchStatusList.size() * batchSize; j < stmtAddedToBatchCount; j++){
PersonBean personValid = personListValidated.get(j);
personValid.setValidationStatus("success");
}
logger.info(lastBatchCount.length + " rows inserted on the last batch");
logger.info("Last batch excuted");
} catch (BatchUpdateException e) {
connection.rollback();
for (int j = batchStatusList.size() * batchSize; j < stmtAddedToBatchCount; j++){
PersonBean personValid = personListValidated.get(j);
personValid.setValidationStatus("fail");
}
logger.error("Last batch fail to execute: " + e, e);
}
writeValidationStatusToCSV(personList);
logger.info("TABLE UPDATE FINISHED");
}