Java Either类代码示例

import scala.util.Either; //导入依赖的package包/类
private InterpreterResult executeSql(String sql) {
  try {
    Either<String, Either<Joiner4All, Mapper4All>> result = dDriver.query(sql, null);
    if (result.isLeft()) {
      return new InterpreterResult(Code.ERROR, result.left().get().toString());
    }
    Either<Joiner4All, Mapper4All> goodResult =
        (Either<Joiner4All, Mapper4All>) result.right().get();
    if (goodResult.isLeft()) {
      return new InterpreterResult(Code.SUCCESS, goodResult.left().get().toString());
    } else {
      return new InterpreterResult(Code.SUCCESS,
        mapper4All2Zeppelin((Mapper4All) goodResult.right().get()));
    }

  } catch (Exception e) {
    return new InterpreterResult(Code.ERROR, e.getMessage());
  }

}
 

import scala.util.Either; //导入依赖的package包/类
private CellEditor getEnumCellEditor(TreeNode node) {
    final ValueData vd = getVD(node);
    final EnumLike enumLike = (EnumLike)vd.element().thype();
    final Object[] values = Interop.toArray(enumLike.values(node));

    for(int i = 0; i < values.length; ++i) {
        Either<String, Object> e = enumLike.interpOut(node, values[i]);
        if(e.isRight()) {
            values[i] = Interop.literal(e.right().get());    
        }
        else {
            values[i] = e.left().get();
        }
    }

    return getSelectCellEditor(true, values);
}
 

import scala.util.Either; //导入依赖的package包/类
private GremlinQuery toGremlinQuery(String query, int limit, int offset) throws AtlasBaseException {
    QueryParams params = validateSearchParams(limit, offset);
    Either<NoSuccess, Expression> either = QueryParser.apply(query, params);

    if (either.isLeft()) {
        throw new AtlasBaseException(DISCOVERY_QUERY_FAILED, query);
    }

    Expression   expression      = either.right().get();
    Expression   validExpression = QueryProcessor.validate(expression);
    GremlinQuery gremlinQuery    = new GremlinTranslator(validExpression, graphPersistenceStrategy).translate();

    if (LOG.isDebugEnabled()) {
        LOG.debug("Translated Gremlin Query: {}", gremlinQuery.queryStr());
    }

    return gremlinQuery;
}
 

import scala.util.Either; //导入依赖的package包/类
private ValidatingTypeCache findTypeLookupsDuringQueryParsing(String query) throws AtlasException {
    TypeSystem typeSystem = TypeSystem.getInstance();
    ValidatingTypeCache result = new ValidatingTypeCache();
    typeSystem.setTypeCache(result);
    typeSystem.reset();
    HierarchicalTypeDefinition<ClassType> hiveTypeDef = createClassTypeDef("hive_db", "", ImmutableSet.<String>of(),
            createRequiredAttrDef("name", DataTypes.STRING_TYPE),
            createRequiredAttrDef("tableCount", DataTypes.INT_TYPE)
    );
    typeSystem.defineClassType(hiveTypeDef);

    Either<Parsers.NoSuccess, Expressions.Expression> either = QueryParser.apply(query, null);
    Expressions.Expression expression = either.right().get();

    QueryProcessor.validate(expression);

    return result;
}
 

import scala.util.Either; //导入依赖的package包/类
public Object handle(Request request, Response response) throws Exception {
    KoauthRequest koauthRequest = requestMapper.map(request);
    Either<KoauthResponse, String> authentication = provider.oauthenticate(koauthRequest);
    if (authentication.isLeft()) {
        KoauthResponse left = authentication.left().get();
        if (left.getClass().equals(ResponseUnauthorized.class)) {
            response.status(401);
            return "You are treated as a guest.\n" + ((ResponseUnauthorized) left).body();
        } else {
            response.status(400);
            return "You are treated as a guest.\n" + ((ResponseBadRequest) left).body();
        }
    } else {
        String username = authentication.right().get();
        return "You are " + username + ".";
    }
}
 

import scala.util.Either; //导入依赖的package包/类
@NotNull
private static Either<ExecError, VersionTriple> getVersion(HaskellToolsConsole toolConsole, String workingDirectory, String hlintPath) {
    return EitherUtil.rightFlatMap(
        runHlint(toolConsole, workingDirectory, hlintPath, "--version"),
        new AbstractFunction1<String, Either<ExecError, VersionTriple>>() {
            @Override
            public Either<ExecError, VersionTriple> apply(String version) {
                Matcher m = HLINT_VERSION_REGEX.matcher(version);
                if (!m.find()) {
                    return new ExecError(
                        "Could not parse version from hlint: '" + version + "'",
                        null
                    ).toLeft();
                }
                return EitherUtil.right(new VersionTriple(
                    Integer.parseInt(m.group(1)),
                    Integer.parseInt(m.group(2)),
                    Integer.parseInt(m.group(3))
                ));
            }
        }
    );
}
 

import scala.util.Either; //导入依赖的package包/类
/**
 * Runs hlintProg with parameters if hlintProg can be executed.
 */
@NotNull
private static Either<ExecError, String> runHlint(HaskellToolsConsole toolConsole,
                                                  @NotNull String workingDirectory,
                                                  @NotNull String hlintProg,
                                                  @NotNull String hlintFlags,
                                                  @NotNull String... params) {
    GeneralCommandLine commandLine = new GeneralCommandLine();
    commandLine.setWorkDirectory(workingDirectory);
    commandLine.setExePath(hlintProg);
    ParametersList parametersList = commandLine.getParametersList();
    // Required so that hlint won't report a non-zero exit status for lint issues.
    // Otherwise, ExecUtil.readCommandLine will return an error.
    parametersList.add("--no-exit-code");
    parametersList.addParametersString(hlintFlags);
    parametersList.addAll(params);
    toolConsole.writeInput(ToolKey.HLINT_KEY, "Using working directory: " + workingDirectory);
    toolConsole.writeInput(ToolKey.HLINT_KEY, commandLine.getCommandLineString());
    return ExecUtil.readCommandLine(commandLine);
}
 

import scala.util.Either; //导入依赖的package包/类
protected void requireCabalVersionMinimum(double minimumVersion, @NotNull String errorMessage) throws RuntimeConfigurationException {
    final HaskellBuildSettings buildSettings = HaskellBuildSettings.getInstance(getProject());
    final String cabalPath = buildSettings.getCabalPath();
    if (cabalPath.isEmpty()) {
        throw new RuntimeConfigurationError("Path to cabal is not set.");
    }
    GeneralCommandLine cabalCmdLine = new GeneralCommandLine(cabalPath, "--numeric-version");
    Either<ExecUtil.ExecError, String> result = ExecUtil.readCommandLine(cabalCmdLine);
    if (result.isLeft()) {
        //noinspection ThrowableResultOfMethodCallIgnored
        ExecUtil.ExecError e = EitherUtil.unsafeGetLeft(result);
        NotificationUtil.displaySimpleNotification(
            NotificationType.ERROR, getProject(), "cabal", e.getMessage()
        );
        throw new RuntimeConfigurationError("Failed executing cabal to check its version: " + e.getMessage());
    }
    final String out = EitherUtil.unsafeGetRight(result);
    final Matcher m = EXTRACT_CABAL_VERSION_REGEX.matcher(out);
    if (!m.find()) {
        throw new RuntimeConfigurationError("Could not parse cabal version: '" + out + "'");
    }
    final Double actualVersion = Double.parseDouble(m.group(1));
    if (actualVersion < minimumVersion) {
        throw new RuntimeConfigurationError(errorMessage);
    }
}
 

import scala.util.Either; //导入依赖的package包/类
/**
 * All commands. If data is null then GET else POST.
 *
 * @return
 */
private Either<String, Either<JSONArray, JSONObject>> fireCommand(String endPoint, String optData, Map<String, String> reqHeaders) {
    CloseableHttpResponse resp = null;
    String respStr;
    String url = format(coordinatorUrl + endPoint, coordinatorHost, coordinatorPort);
    try {
        if (optData != null) {// POST
            resp = postJson(url, optData, reqHeaders);
        } else {// GET
            resp = get(url, reqHeaders);
        }
        respStr = IOUtils.toString(resp.getEntity().getContent());
    } catch (IOException ex) {
        return new Left<>(format("Http %s, faced exception %s\n", resp, ex));
    } finally {
        returnClient(resp);
    }
    try {
        return new Right<>(Util.asJsonType(respStr));
    } catch (JSONException je) {
        return new Left<>(format("Recieved data %s not in json format, faced exception %s\n", respStr, je));
    }
}
 

import scala.util.Either; //导入依赖的package包/类
/**
 * Left is error Right is Tuple <dimensions, metrics>
 *
 * @param name
 * @param reqHeaders
 * @return
 */
public Either<String, Tuple2<List<String>, List<String>>> aboutDataSource(String name, Map<String, String> reqHeaders) {
    Either<String, Either<JSONArray, JSONObject>> resp = fireCommand("druid/coordinator/v1/metadata/datasources/" + name, null, reqHeaders);
    if (resp.isLeft()) {
        return new Left<>(resp.left().get());
    }
    Either<JSONArray, JSONObject> goodResp = resp.right().get();
    if (goodResp.isRight()) {
        JSONObject data = goodResp.right().get();
        if (data.has("segments")) {
            JSONArray segmentsArray = data.getJSONArray("segments");
            if (segmentsArray.length() == 0) {
                return new Left<>("No segments received..");
            }
            JSONObject firstItem = segmentsArray.getJSONObject(0);
            String dims = firstItem.getString("dimensions");
            String metrics = firstItem.getString("metrics");
            return new Right<>(new Tuple2<>(Arrays.asList(dims.split(",")), Arrays.asList(metrics.split(","))));
        } else {
            return new Left<>("No segments key in the response..");
        }
    }
    return new Left<>("Unexpected response " + goodResp.left().get().toString());
}
 

import scala.util.Either; //导入依赖的package包/类
/**
 * For firing simple queries(i.e non join queries).
 *
 * @param jsonQuery
 * @param reqHeaders
 * @param requiresMapping
 * @return
 */
public Either<String, Either<Mapper4All, JSONArray>> fireQuery(String jsonQuery, Map<String, String> reqHeaders, boolean requiresMapping) {
    CloseableHttpResponse resp = null;
    String respStr;
    String url = format(brokerUrl, brokerHost, brokerPort);
    try {
        resp = postJson(url, jsonQuery, reqHeaders);
        respStr = IOUtils.toString(resp.getEntity().getContent());
    } catch (IOException ex) {
        return new Left<>(format("Http %s, faced exception %s\n", resp, ex));        
    } finally {
        returnClient(resp);
    }
    JSONArray possibleResArray = null;
    try {
        possibleResArray = new JSONArray(respStr);
    } catch (JSONException je) {
        return new Left<>(format("Recieved data %s not in json format. \n", respStr));
    }
    if (requiresMapping) {
        return new Right<String, Either<Mapper4All, JSONArray>>(new Left<Mapper4All, JSONArray>(new Mapper4All(possibleResArray)));
    }
    return new Right<String, Either<Mapper4All, JSONArray>>(new Right<Mapper4All, JSONArray>(possibleResArray));
}
 

import scala.util.Either; //导入依赖的package包/类
/**
 * Get timeboundary.
 *
 * @param dataSource 
 * @param reqHeaders 
 * @return
 * @throws java.lang.IllegalAccessException
 */
public Interval getTimeBoundary(String dataSource, Map<String, String> reqHeaders) throws IllegalAccessException {
    Program<BaseStatementMeta> pgm = DCompiler.compileSql(format("SELECT FROM %s", dataSource));
    Either<String,Either<Mapper4All,JSONArray>> res = fireQuery(pgm.nthStmnt(0).toString(), reqHeaders, true);
    if (res.isLeft()) {
        throw new IllegalAccessException(format("DataSource %s does not exist(or) check if druid is accessible, faced exception %s", dataSource, res.left().get()));
    }
    Mapper4All finalRes = res.right().get().left().get();// Thats because we know Time boundary cannot be a Join result!!
    int min = finalRes.baseFieldNames.indexOf("minTime");
    int max = finalRes.baseFieldNames.indexOf("maxTime");
    if (finalRes.baseAllRows.isEmpty()) {// Possible when table does not exist.
        throw new IllegalAccessException("Either table does not exist(or) druid is not accessible");
    }
    List<Object> row = finalRes.baseAllRows.get(0);// Only 1 element is returned in Timeboundary.
    return new Interval(row.get(min).toString(), row.get(max).toString());
}
 

import scala.util.Either; //导入依赖的package包/类
/**
 * Get an in memory representation of broken SQL query. This may require 
 * contacting druid for resolving dimensions Vs metrics for SELECT queries
 * hence it also optionally accepts HTTP request headers to be sent out.
 *
 * @param sqlQuery
 * @param namedParams
 * @param reqHeaders
 * @return
 * @throws java.lang.Exception
 */
public Program<BaseStatementMeta> getCompiledAST(String sqlQuery, NamedParameters namedParams, Map<String, String> reqHeaders) throws Exception {
    Program<BaseStatementMeta> pgm = DCompiler.compileSql(preprocessSqlQuery(sqlQuery, namedParams));
    for (BaseStatementMeta stmnt : pgm.getAllStmnts()) {
        if (stmnt instanceof QueryMeta) {
            QueryMeta query = (QueryMeta) stmnt;
            if (query.queryType == RequestType.SELECT) {//classifyColumnsToDimAndMetrics
                Either<String, Tuple2<List<String>, List<String>>> dataSourceDescRes = coordinator.aboutDataSource(stmnt.dataSource, reqHeaders);
                if (dataSourceDescRes.isLeft()) {
                    throw new Exception("Datasource info either not available (or)could not be loaded ." + dataSourceDescRes.left().get());
                } else {
                    ((SelectQueryMeta) query).postProcess(dataSourceDescRes.right().get());
                }
            }
        } else if (stmnt instanceof InsertMeta) {//TODO: Handle this.

        } else if (stmnt instanceof DeleteMeta) {//TODO: Handle this.

        } else if (stmnt instanceof DropMeta) {//TODO: Handle this.

        }
    }
    //TODO: Do something if pgm is invalid !!!
    pgm.isValid();
    return pgm;
}
 

import scala.util.Either; //导入依赖的package包/类
@Override
public void write(RowLocation rowLocation, Either<Exception, ExecRow> value) throws IOException, InterruptedException {
    if (value.isLeft()) {
        Exception e = value.left().get();
        // failure
        failure = true;
        SpliceLogUtils.error(LOG,"Error Reading",e);
        throw new IOException(e);
    }
    assert value.isRight();
    ExecRow execRow = value.right().get();
    try {
        if (!initialized) {
            initialized = true;
            tableWriter.open();
        }
        tableWriter.write(execRow);
    } catch (Exception se) {
        SpliceLogUtils.error(LOG,"Error Writing",se);
        failure = true;
        throw new IOException(se);
    }
}
 

import scala.util.Either; //导入依赖的package包/类
@Override
public RecordWriter<byte[],Either<Exception, KVPair>> getRecordWriter(TaskAttemptContext taskAttemptContext) throws IOException, InterruptedException {
    try {
        assert taskAttemptContext != null && taskAttemptContext.getConfiguration() != null:"configuration passed in is null";
        if (outputCommitter == null)
            getOutputCommitter(taskAttemptContext);
        DataSetWriterBuilder tableWriter =TableWriterUtils.deserializeTableWriter(taskAttemptContext.getConfiguration());
        TxnView childTxn = outputCommitter.getChildTransaction(taskAttemptContext.getTaskAttemptID());
        if (childTxn == null)
            throw new IOException("child transaction lookup failed");
        tableWriter.txn(childTxn);
        return new HTableRecordWriter(tableWriter.buildTableWriter(), outputCommitter);
    } catch (Exception e) {
        throw new IOException(e);
    }
}