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java - 性能解析 Csv 到 bean java

问题描述

无法读取 csv 文件有超过 500 万行

环境：Java 8、opencsv -version 4.6、Lunix、MySQL

我的代码：

public static <T> List<T> parseCsvToBeanPosition(Class<T> clazz, Reader readerInput) {
        ColumnPositionMappingStrategy ms = new ColumnPositionMappingStrategy();
        ms.setType(clazz);
        CsvToBean<T> csvToBean =
                new CsvToBeanBuilder(readerInput)
                        .withType(clazz)
                        .withMappingStrategy(ms)
                        .build();
        return csvToBean.parse();
    }

2019-06-21 16:38:13 [http-nio-8085-exec-2] INFO SynchronizeBusiness - Start parse:  (SynchronizeBusiness.java:223)
Java HotSpot(TM) 64-Bit Server VM warning: INFO: os::commit_memory(0x00000000abc80000, 284688384, 0) failed; error='Cannot allocate memory' (errno=12)
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 284688384 bytes for committing reserved memory.
# An error report file with more information is saved as:

标签： javaread.csv

解决方案

看起来您的应用程序消耗的内存多于分配的内存（默认）。

  1. 将分配给 JVM 的内存增加到 -Xms2g -Xmx2g （如果需要增加更多并尝试一下）

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