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尝试将 java resultSet 数据转换为 R 中的 data.frame。最多 5 行没有问题。但是当超过 5 条记录正在转换时，会出现错误“语法错误，意外 SYMBOL，期待 ','”

public static void main(String[] args) throws ScriptException, FileNotFoundException {
        RenjinScriptEngineFactory factory = new RenjinScriptEngineFactory();
        ScriptEngine engine = factory.getScriptEngine();
        engine.eval("source(\"script.R\")");
        engine.eval("workflow.predict("+getData()+")");
    }

    public static ListVector getData() {
        Connection connection = null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;
        StringArrayVector.Builder userid = new StringArrayVector.Builder();
        StringArrayVector.Builder defaultCC = new StringArrayVector.Builder();
        StringArrayVector.Builder typeId = new StringArrayVector.Builder();
        StringArrayVector.Builder amount = new StringArrayVector.Builder();
        StringArrayVector.Builder cc = new StringArrayVector.Builder();
        StringArrayVector.Builder activity = new StringArrayVector.Builder();
        try{
            String query = "select top 6 wi.owner_user_id as userId, u.cost_center_id as defaultCC, li.expense_type_id typeId, wi.doc_specific_amount as amount, al.cost_center_id as cc,wi.activity_id as activity from alwf_work_item wi, alco_user u, aler_expense_line_item li,aler_line_allocation al where u.user_id = wi.owner_user_id and wi.business_object_id=li.parent_id and li.exp_line_item_id=al.exp_line_item_id";
            connection = getConnection();
            statement = connection.prepareStatement(query);
            resultSet = statement.executeQuery();
            while(resultSet.next()) {
                userid.add(resultSet.getLong("userId"));
                defaultCC.add(resultSet.getLong("defaultCC"));
                typeId.add(resultSet.getLong("typeId"));
                amount.add(resultSet.getLong("amount"));
                cc.add(resultSet.getLong("cc"));
                activity.add(resultSet.getLong("activity"));
            }
        }catch (Exception e) {
            e.printStackTrace();
        }
        ListVector.NamedBuilder myDf = new ListVector.NamedBuilder();
        myDf.setAttribute(Symbols.CLASS, StringVector.valueOf("data.frame"));
        myDf.setAttribute(Symbols.ROW_NAMES, new RowNamesVector(userid.length())); 
        myDf.add("userId", userid.build());
        myDf.add("defaultCC", defaultCC.build());
        myDf.add("typeId", typeId.build());
        myDf.add("amount", amount.build());
        myDf.add("cc", cc.build());
        myDf.add("activity", activity.build());
        return myDf.build();
    }

R 脚本

workflow.predict <- function(abc) {
    print(abc)
    print(data.frame(lapply(abc, as.character), stringsAsFactors=FALSE))
    dataset = data.frame(lapply(abc, as.character), stringsAsFactors=FALSE)
    library(randomForest)
    classifier = randomForest(x = dataset[-6], y = as.factor(dataset$activity))
    new.data=c(62020,3141877,46013,950,3141877)
    y_pred = predict(classifier, newdata = new.data)
    print(y_pred)
    return(y_pred)
}

以下是使用前 6 条记录运行脚本时出现的错误。但对于前 5 名记录，它运行时没有任何错误。提前致谢。

Exception in thread "main" org.renjin.parser.ParseException: Syntax error at 1 68 1 70 68 70: syntax error, unexpected SYMBOL, expecting ','
    at org.renjin.parser.RParser.parseAll(RParser.java:146)
    at org.renjin.parser.RParser.parseSource(RParser.java:69)
    at org.renjin.parser.RParser.parseSource(RParser.java:122)
    at org.renjin.parser.RParser.parseSource(RParser.java:129)
    at org.renjin.script.RenjinScriptEngine.eval(RenjinScriptEngine.java:127)
    at RTest.main(RTest.java:27)

结果集的样本数据在这里

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1 回答 1

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通过使用Builder userid = new ListVector.Builder()而不是StringArrayVector.Builder userid = new StringArrayVector.Builder()它接受更多记录而没有任何错误。我不确定为什么StringArrayVector仅限于 5 条记录。

于 2019-09-06T11:29:25.457 回答