软件工程-第二次作业

1 tar -xvzf jdk-8u101-linux-x64.tar.gz

1 sudo vi /etc/profile

 1 # /etc/profile: system-wide .profile file for the Bourne shell (sh(2))
 2 # and Bourne compatible shells (bash(1), ksh(1), ash(1), ...).
 3 
 4 if [ "$PS1" ]; then
 5   if [ "$BASH" ] && [ "$BASH" != "/bin/sh" ]; then
 6     # The file bash.bashrc already sets the default PS1.
 7     # PS1=‘\h:\w\$ ‘
 8     if [ -f /etc/bash.bashrc ]; then
 9       . /etc/bash.bashrc
10     fi
11   else
12     if [ "`id -u`" -eq 0 ]; then
13       PS1=‘# ‘
14     else
15       PS1=‘$ ‘
16     fi
17   fi
18 fi
19 
20 # The default umask is now handled by pam_umask.
21 # See pam_umask(8) and /etc/login.defs.
22 
23 if [ -d /etc/profile.d ]; then
24   for i in /etc/profile.d/*.sh; do
25     if [ -r $i ]; then
26       . $i
27     fi
28   done
29   unset i
30 fi
31 export JAVA_HOME=/home/jiali/jdk1.8.0_101
32 export PATH=$JAVA_HOME/bin:$PATH
33 export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
34 ~  

 1 jiali@peerslee-521:~$ source /etc/profile
 2 jiali@peerslee-521:~$ java
 3 Usage: java [-options] class [args...]
 4            (to execute a class)
 5    or  java [-options] -jar jarfile [args...]
 6            (to execute a jar file)
 7 where options include:
 8     -d32      use a 32-bit data model if available
 9     -d64      use a 64-bit data model if available
10     -server      to select the "server" VM
11                   The default VM is server,
12                   because you are running on a server-class machine.
13 
14 
15     -cp <class search path of directories and zip/jar files>
16     -classpath <class search path of directories and zip/jar files>
17                   A : separated list of directories, JAR archives,
18                   and ZIP archives to search for class files.
19     -D<name>=<value>
20                   set a system property
21     -verbose:[class|gc|jni]
22                   enable verbose output
23     -version      print product version and exit
24     -version:<value>
25                   Warning: this feature is deprecated and will be removed
26                   in a future release.
27                   require the specified version to run
28     -showversion  print product version and continue
29     -jre-restrict-search | -no-jre-restrict-search
30                   Warning: this feature is deprecated and will be removed
31                   in a future release.
32                   include/exclude user private JREs in the version search
33     -? -help      print this help message
34     -X            print help on non-standard options
35     -ea[:<packagename>...|:<classname>]
36     -enableassertions[:<packagename>...|:<classname>]
37                   enable assertions with specified granularity
38     -da[:<packagename>...|:<classname>]
39     -disableassertions[:<packagename>...|:<classname>]
40                   disable assertions with specified granularity
41     -esa | -enablesystemassertions
42                   enable system assertions
43     -dsa | -disablesystemassertions
44                   disable system assertions
45     -agentlib:<libname>[=<options>]
46                   load native agent library <libname>, e.g. -agentlib:hprof
47                   see also, -agentlib:jdwp=help and -agentlib:hprof=help
48     -agentpath:<pathname>[=<options>]
49                   load native agent library by full pathname
50     -javaagent:<jarpath>[=<options>]
51                   load Java programming language agent, see java.lang.instrument
52     -splash:<imagepath>
53                   show splash screen with specified image
54 See http://www.oracle.com/technetwork/java/javase/documentation/index.html for more details.
55 jiali@peerslee-521:~$ javac
56 Usage: javac <options> <source files>
57 where possible options include:
58   -g                         Generate all debugging info
59   -g:none                    Generate no debugging info
60   -g:{lines,vars,source}     Generate only some debugging info
61   -nowarn                    Generate no warnings
62   -verbose                   Output messages about what the compiler is doing
63   -deprecation               Output source locations where deprecated APIs are used
64   -classpath <path>          Specify where to find user class files and annotation processors
65   -cp <path>                 Specify where to find user class files and annotation processors
66   -sourcepath <path>         Specify where to find input source files
67   -bootclasspath <path>      Override location of bootstrap class files
68   -extdirs <dirs>            Override location of installed extensions
69   -endorseddirs <dirs>       Override location of endorsed standards path
70   -proc:{none,only}          Control whether annotation processing and/or compilation is done.
71   -processor <class1>[,<class2>,<class3>...] Names of the annotation processors to run; bypasses default discovery process
72   -processorpath <path>      Specify where to find annotation processors
73   -parameters                Generate metadata for reflection on method parameters
74   -d <directory>             Specify where to place generated class files
75   -s <directory>             Specify where to place generated source files
76   -h <directory>             Specify where to place generated native header files
77   -implicit:{none,class}     Specify whether or not to generate class files for implicitly referenced files
78   -encoding <encoding>       Specify character encoding used by source files
79   -source <release>          Provide source compatibility with specified release
80   -target <release>          Generate class files for specific VM version
81   -profile <profile>         Check that API used is available in the specified profile
82   -version                   Version information
83   -help                      Print a synopsis of standard options
84   -Akey[=value]              Options to pass to annotation processors
85   -X                         Print a synopsis of nonstandard options
86   -J<flag>                   Pass <flag> directly to the runtime system
87   -Werror                    Terminate compilation if warnings occur
88   @<filename>                Read options and filenames from file
89 94 jiali@peerslee-521:~$ java -version
95 java version "1.8.0_101"
96 Java(TM) SE Runtime Environment (build 1.8.0_101-b13)
97 Java HotSpot(TM) 64-Bit Server VM (build 25.101-b13, mixed mode)

1 tar -xvf eclipse-jee-neon-1-linux-gtk-x86_64.tar.gz 

 1 package p01;
 2 public class MaxSubArraySum {  
 3     public static void main(String []args) {  
 4         /* 
 5          * 测试数组 
 6          */  
 7         int []arr1 = {1, 1, 1, 1, 1, 1};  
 8         int []arr2 = {0, 0, 0, 0, 0, 0};  
 9         int []arr3 = {-9, -2, -3, -5, -3};  
10         int []arr4 = {1, -2, 3, 5, -3, 2};  
11         int []arr5 = {0, -2, 3, 5, -1, 2};  
12           
13         /* 
14          * 测试结果 
15          */  
16         System.out.println(  
17                 "+：\t" + maxSum(arr1) + "\n" +  
18                 "0：\t" + maxSum(arr2) + "\n" +  
19                 "-：\t" + maxSum(arr3) + "\n" +  
20                 "+-：\t" + maxSum(arr4) + "\n" +  
21                 "+0-：\t" + maxSum(arr5)    
22                 );  
23           
24     }  
25       
26     static int maxSum(int []arr) {  
27         int nStart = arr[0];  
28         int nAll = arr[0];  
29           
30         /* 
31          * 动态规划： 
32          * max{arr[i],arr[i]+start[i+1],all[i]} 
33          * 注： 
34          * arr[i] -> 第 i 个数值 
35          * arr[i] + start[i+1] -> 第 i 个 数值 加上 下一个数值 
36          * all[i] -> 当前最大子数组和 
37          */  
38         for(int i = 1; i < arr.length; i++) {  
39             nStart = Math.max(arr[i], arr[i]+nStart);  
40             nAll = Math.max(nStart, nAll);  
41         }  
42         return nAll;  
43     }  
44 }