在shell中,我在Impatient / part1目录中input了gradle cleanJar 。 输出如下。 错误是“ 未findorg.apache.hadoop.mapred.JobConf的类文件 ”。 为什么它不能编译? :clean UP-TO-DATE :compileJava Download http://conjars.org/repo/cascading/cascading-core/2.0.1/cascading-core-2.0.1.pom Download http://conjars.org/repo/cascading/cascading-hadoop/2.0.1/cascading-hadoop-2.0.1.pom Download http://conjars.org/repo/riffle/riffle/0.1-dev/riffle-0.1-dev.pom Download http://repo1.maven.org/maven2/org/slf4j/slf4j-api/1.6.1/slf4j-api-1.6.1.pom Download http://repo1.maven.org/maven2/org/slf4j/slf4j-parent/1.6.1/slf4j-parent-1.6.1.pom Download http://repo1.maven.org/maven2/org/slf4j/slf4j-log4j12/1.6.1/slf4j-log4j12-1.6.1.pom Download http://conjars.org/repo/thirdparty/jgrapht-jdk1.6/0.8.1/jgrapht-jdk1.6-0.8.1.pom Download http://repo1.maven.org/maven2/org/codehaus/janino/janino/2.5.16/janino-2.5.16.pom Download http://conjars.org/repo/cascading/cascading-core/2.0.1/cascading-core-2.0.1.jar Download http://conjars.org/repo/cascading/cascading-hadoop/2.0.1/cascading-hadoop-2.0.1.jar Download http://conjars.org/repo/riffle/riffle/0.1-dev/riffle-0.1-dev.jar Download http://repo1.maven.org/maven2/org/slf4j/slf4j-api/1.6.1/slf4j-api-1.6.1.jar Download http://repo1.maven.org/maven2/org/slf4j/slf4j-log4j12/1.6.1/slf4j-log4j12-1.6.1.jar Download http://conjars.org/repo/thirdparty/jgrapht-jdk1.6/0.8.1/jgrapht-jdk1.6-0.8.1.jar Download http://repo1.maven.org/maven2/org/codehaus/janino/janino/2.5.16/janino-2.5.16.jar /home/is_admin/lab/cascading/Impatient/part1/src/main/java/impatient/Main.java:50: error: cannot access JobConf Tap inTap = new Hfs( new TextDelimited( […]
为什么Scala和Spark和foldLeft这样的框架同时具有reduce和foldLeft ? 那么reduce和fold什么区别呢?