社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 9643阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* 1ux~dP  
**SiteFileFetch.java <n< @ O5  
*/ I^ sWf3'db  
package NetFox; Au &NQ+  
import java.io.*; VQV7W  
import java.net.*; GJW+'-f  
p"f=[awp  
2j8^Z  
public class SiteFileFetch extends Thread { ^:W.R7|  
Ac!,#Fq  
ik02Q,J  
SiteInfoBean siteInfoBean = null; //文件信息Bean _,(]T&j #2  
long[] nStartPos; //开始位置 HB yk 1  
long[] nEndPos; //结束位置 w-\U;&8  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 qW[p .jN  
long nFileLength; //文件长度 JCZ"#8M3  
boolean bFirst = true; //是否第一次取文件 b;K>Q!(|  
boolean bStop = false; //停止标志 rRyBGEj  
File tmpFile; //文件下载的临时信息 L+2!Sc,>  
DataOutputStream output; //输出到文件的输出流 `'9Kj9}   
J&%vBg^  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ei'=%r8~  
public SiteFileFetch(SiteInfoBean bean) throws IOException qG3 [5lti  
{ 2)]C'  
siteInfoBean = bean; -]"=b\Q  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); dk~h  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Dv?'(.z  
if(tmpFile.exists ()) +N1oOcPC>C  
{ HVaWv].  
bFirst = false; 8$a4[s  
read_nPos(); bUbM}  
} *m:h0[[J  
else IQ[ ?ej3W  
{ *%_:[>  
nStartPos = new long[bean.getNSplitter()]; 4q o4g+  
nEndPos = new long[bean.getNSplitter()]; e:}8|e~T  
} u38FY@U$  
-C.x;@!k  
d&'z0]mOe  
+F q`I2l|  
} yyZH1A  
vr5 6 f1  
 s#om  
public void run() Wh[+cH"M  
{ K1#Y{k5D}  
//获得文件长度 yZ3/Ia>,  
//分割文件 3;=nQ{0b  
//实例FileSplitterFetch u%?u`n2'  
//启动FileSplitterFetch线程 |qbCmsY5/  
//等待子线程返回 b9%}< w  
try{ I7b(fc-r  
if(bFirst) qQN&uBQ[  
{ ~d6 _  
nFileLength = getFileSize(); dgPJte%i  
if(nFileLength == -1) avxI\twAU  
{ wm0vqY+N$  
System.err.println("File Length is not known!"); b $x<7l5C  
} U I|L;5  
else if(nFileLength == -2) ie+&@u  
{ hH:7  
System.err.println("File is not access!"); p.i$[6M  
} I!lzOg4~  
else zMb7a_W  
{ adtK$@Yeg  
for(int i=0;i<nStartPos.length;i++) K6=-Zf  
{ 3=~"<f l  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 5} |O  
} _i~n!v  
for(int i=0;i<nEndPos.length-1;i++) d_#\^!9  
{ g6 EdCG.V  
nEndPos = nStartPos[i+1]; XPXC7_fV  
} !OM9aITv[  
nEndPos[nEndPos.length-1] = nFileLength; g.aNITjP  
} Pa 2HFy2  
} \@nmM&7C!4  
B5Rmz&  
zNRoFz.  
//启动子线程 U,)Ngnd  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (FZL>  
for(int i=0;i<nStartPos.length;i++) ?@Z~i]gE[V  
{ 6"WR}S0o  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d+~c$(M)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), JGt4B  
nStartPos,nEndPos,i); hZI9*= `,"  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M]!\X6<_  
fileSplitterFetch.start(); AC,$(E  
} kac@yQD  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 94I8~Jj4  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TveCy&  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (xK=/()}q  
nEndPos = " + nFileLength); &q1(v3cOO  
// fileSplitterFetch[nPos.length-1].start(); |Z6rP-  
x(3E#7>1  
`ea;qWy  
//等待子线程结束 U jVo "K  
//int count = 0; tr7FV1p  
//是否结束while循环 %^^2  
boolean breakWhile = false; k='sI^lF  
btw_k+Fh  
Svn|vH  
while(!bStop) Jjik~[<q:  
{ Eag->mw/~  
write_nPos();  \A:m<::  
Utility.sleep(500); $y\'j5nk3  
breakWhile = true; h3a HCr E  
m\U@L+L  
+Es3iE @  
for(int i=0;i<nStartPos.length;i++) 2|tZ xlt-  
{ Cst\_j  
if(!fileSplitterFetch.bDownOver) fS-#dJC";`  
{ v[CX-CBZ?  
breakWhile = false; V!c{%zd  
break; 8~:qn@ Z|E  
} G9z Q{E  
} T_6,o[b8  
if(breakWhile) 4 u X<sJ*  
break; m^U\l9LE  
9+@_ZI-  
_.J{U0N  
//count++; "KOLRJ@  
//if(count>4) /+2^xEIjE  
// siteStop(); =w".B[r  
} s?=f,I  
Cv{rd##Y8  
xex/L%!Rj  
System.err.println("文件下载结束!"); y_qFXd  
} x_v pds  
catch(Exception e){e.printStackTrace ();} VyCBJK  
} #1z}~1-  
:Ff1Js(Z  
q{ @>2AlK  
//获得文件长度 Gi]Pwo${  
public long getFileSize() U;OJ.a9  
{ 4&K~EX"^T  
int nFileLength = -1; /4w&! $M-  
try{ M=26@ n  
URL url = new URL(siteInfoBean.getSSiteURL()); r4Pm i  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2aW&d=!ZV  
httpConnection.setRequestProperty("User-Agent","NetFox"); qB3 SQ:y  
qQ/j+  
bY+Hf\A  
int responseCode=httpConnection.getResponseCode(); HkJ$r<J2  
if(responseCode>=400) lj@c"Yrk  
{ ff?:_q+.N  
processErrorCode(responseCode); #p*{p)]HiA  
return -2; //-2 represent access is error l *yml  
} +_06{7@h  
Th`IpxV  
z]=A3!H/Y  
String sHeader; zvdtP'&uj  
"%<Oadz ap  
vov"60K  
for(int i=1;;i++) 6 jRF[N8  
{ 7>wSbAR<  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;,JCA# N  
//Utility.log(in.readLine()); 53=s'DZ  
sHeader=httpConnection.getHeaderFieldKey(i); t 4{{5U'\  
if(sHeader!=null) @/`b:sv&*  
{ d.% Vm&3  
if(sHeader.equals("Content-Length")) fwf]1@#   
{ OY51~#BF  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LC*@ /((  
break; u(\b1h n  
} )e4nKh],  
} D/9&pRsO  
else |mc!v*O  
break; i=o<\ {iV:  
} tl CgW)<?  
} xx#; )]WT  
catch(IOException e){e.printStackTrace ();} g(,gg1mG  
catch(Exception e){e.printStackTrace ();} gK9@-e  
55zimv&DV  
iU~oPp[e  
Utility.log(nFileLength); 0KHA5dt  
.?<,J  
kZ[E493bV  
return nFileLength; 7$\;G82_  
} S$=])^dur  
cmZ39pjBJ  
A>bo Xcr  
//保存下载信息(文件指针位置) Qg%B<3 <  
private void write_nPos() n* 9)Y~  
{ b_|`jHes  
try{ <I&X[Sqp  
output = new DataOutputStream(new FileOutputStream(tmpFile)); t1 OnA#]/_  
output.writeInt(nStartPos.length); 54-sb~]  
for(int i=0;i<nStartPos.length;i++) SYw>P1  
{ K!).QB'  
// output.writeLong(nPos); "/S-+Ufn  
output.writeLong(fileSplitterFetch.nStartPos); }{n[_:[7  
output.writeLong(fileSplitterFetch.nEndPos); dK#:io[Nz  
} nkG1&wiX  
output.close(); Elo m_   
} lOCMKaCD  
catch(IOException e){e.printStackTrace ();} ^I5k+cL  
catch(Exception e){e.printStackTrace ();} MQG(n+c  
} qdx(wGG  
G yvEc3|@  
o 3#qp>R  
//读取保存的下载信息(文件指针位置) Xat>d>nJ]  
private void read_nPos() *_}ft-*w  
{ h rW  
try{ ey_3ah3x  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5*/~) wN\U  
int nCount = input.readInt(); dAh&Z:86\  
nStartPos = new long[nCount]; [1F.   
nEndPos = new long[nCount]; H!y1&  
for(int i=0;i<nStartPos.length;i++) `+CRUdr  
{ `WboM\u  
nStartPos = input.readLong(); yTm/P!1S  
nEndPos = input.readLong(); ]o$aGrZ  
} %c<e`P;  
input.close(); V`fp%7W  
} xA& tVQ2!  
catch(IOException e){e.printStackTrace ();} 8d?r )/~  
catch(Exception e){e.printStackTrace ();} i+ ]3J/J  
} ZP &q7HK\  
x"9`w 42\r  
X4_1kY;  
private void processErrorCode(int nErrorCode) pZ,=iqr  
{ n`8BE9h^  
System.err.println("Error Code : " + nErrorCode); 2F%2K?$`Ej  
} CBN,~wzP*  
fd! bs*\X  
++w7jVi9  
//停止文件下载 R.@I}>  
public void siteStop() XD%@Y~>+  
{ t 1}R#NB  
bStop = true; OyH>N/  
for(int i=0;i<nStartPos.length;i++) "yJFb=Xdq  
fileSplitterFetch.splitterStop(); f^Sl(^f  
o-a\T  
aO)Cq5  
} (yA`h@@WS  
} U2<8U  
//负责部分文件的抓取 4zKmoYt  
**FileSplitterFetch.java 3V=wW{;x  
*/ kn<IWW_t  
package NetFox; K G<. s<  
~8:q-m_h  
2>TOC BB"  
import java.io.*; Oxsx\f_  
import java.net.*; =\~<##sRJ  
~/^q>z!\4  
a;bmZh  
public class FileSplitterFetch extends Thread { /M!b3bmA  
g?B4b7II  
8uAA6h+  
String sURL; //File URL H j [!F%  
long nStartPos; //File Snippet Start Position Rtpk_ND!  
long nEndPos; //File Snippet End Position j/ [V<  
int nThreadID; //Thread's ID <ks+JkW_  
boolean bDownOver = false; //Downing is over 2(I S*idq  
boolean bStop = false; //Stop identical gZq _BY_U  
FileAccessI fileAccessI = null; //File Access interface 41uiW,  
tVQq,_9C  
OFe-e(c1  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XM1; >#kz  
{ \MqOHM.[  
this.sURL = sURL; ;P *`v  
this.nStartPos = nStart; %\"<lyD  
this.nEndPos = nEnd; !E7JDk''@  
nThreadID = id; mqj]=Fq*  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cl04fqX  
} ci 4K Nv;  
9]C%2!Ur,  
sGFvSW  
public void run() Oh# z zo  
{ `6y=ky.,  
while(nStartPos < nEndPos && !bStop) dJv2tVm&'  
{ ] M`%@ps  
[s4|+  
CS'LW;#[  
try{ )Cu2xRr^`  
URL url = new URL(sURL); }#r awVe=  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @yM$Et5  
httpConnection.setRequestProperty("User-Agent","NetFox"); XEegUTs  
String sProperty = "bytes="+nStartPos+"-"; Z_U4Yy'NNw  
httpConnection.setRequestProperty("RANGE",sProperty); j)ME%17  
Utility.log(sProperty); }1 ,\ *)5  
S86,m =  
po\(O8#5U  
InputStream input = httpConnection.getInputStream(); }7*|s+F(f  
//logResponseHead(httpConnection); 7Q^p|;~a  
hCBre5  
iC{(vL0P+  
byte[] b = new byte[1024]; KFg q3snH  
int nRead; OUq%d8 W  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) GQ(*k)'a  
{ e@Mg9VwDc  
nStartPos += fileAccessI.write(b,0,nRead); O^J=19Ri  
//if(nThreadID == 1) gky+.EP.  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4VF4 8  
} +T\<oj%}2  
Mz6\T'rC  
a,36FF~&  
Utility.log("Thread " + nThreadID + " is over!"); x<h|$$4S  
bDownOver = true; V0NLwl O  
//nPos = fileAccessI.write (b,0,nRead); C$p012D1  
} ebn3r:IU-  
catch(Exception e){e.printStackTrace ();} $K.DLqDt  
} + -uQ] ^n  
} f&j\gYWq  
B(WmJ6e  
up{0ehr  
//打印回应的头信息 3[j,d]\|  
public void logResponseHead(HttpURLConnection con) ?q7MbQw  
{ Zs(BViTb|  
for(int i=1;;i++) AyWdJ<OU  
{ eR4ib-nS  
String header=con.getHeaderFieldKey(i); R?zlZS.~  
if(header!=null) -oUGmV_  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x <a}*8"  
Utility.log(header+" : "+con.getHeaderField(header)); 8 :WN@  
else )RN3Oz@H  
break; [n2zdiiBd  
} Zb=;\l*&  
} ;vneeW4|  
gg.]\#3g  
)!kt9lK  
public void splitterStop() \pk9i+t  
{ S{?l/*Il*_  
bStop = true; qdLzB  
} je@&|9h  
>yr;Y4y7K  
e]nP7TIU  
} )H@<A93  
"n]x%. *  
)u+O~Y95&i  
/* CuK>1_Dq  
**FileAccess.java bfpeK>T  
*//文件访问(定位,写) :1Nc6G  
package NetFox; 4evNZ Q  
import java.io.*; e,{k!BXU#'  
 6/#+#T  
{ TI,|'>5[  
public class FileAccessI implements Serializable{ i3mw.`7  
KB^8Z@(+  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OwEV$Q  
RandomAccessFile oSavedFile; !yT=*Cj4  
long nPos; _p0gXb1m`  
f,i2U|1pbj  
x]yIe&*('  
public FileAccessI() throws IOException  [Rub  
{ Op8Gj  `  
this("",0);  Uj\t04  
} }cI-]|)|2  
x${C[gxq9F  
h^_^)P+;  
public FileAccessI(String sName,long nPos) throws IOException 34X]b[^  
{ MM]0}65KG  
oSavedFile = new RandomAccessFile(sName,"rw"); %TRJ  
this.nPos = nPos; cWyf04-?  
oSavedFile.seek(nPos); #'O9Hn({  
} P=1K u|k  
?*$uj(  
Y'jgp Vt  
public synchronized int write(byte[] b,int nStart,int nLen) 5x|$q kI  
{ |EdEV*.ej  
int n = -1; &>+5 8  
try{ g33Y$Xdk  
oSavedFile.write(b,nStart,nLen); J/D~]U  
n = nLen; Du +_dr^4  
} U\, N  
catch(IOException e) ?$ov9U_  
{ lK/4"&  
e.printStackTrace (); ^7ID |uMr  
} *~4<CP+"0  
O-ENFA~E;v  
\1&4wzT  
return n; a * CXg.i  
} FeS ,TQ4j  
olr#3te  
X jxa 2D  
} a!4p$pR  
y{<js!au  
Vt \g9-[  
/* fj['M6+wd  
**SiteInfoBean.java sr[[xzL  
*/ sw}^@0ua=  
package NetFox; x4>"m(&%  
-K$ugDi  
BMQ4i&kF|  
public class SiteInfoBean { !gV{[j?~zr  
OGLA1}k4  
82+2 PE{  
private String sSiteURL; //Site's URL **z^aH?B2  
private String sFilePath; //Saved File's Path =`>ei  
private String sFileName; //Saved File's Name } ,}g](!m  
private int nSplitter; //Count of Splited Downloading File 3!cenyE  
/&G|.Cx  
Het>G{  
public SiteInfoBean() 6C"zBJcGc  
{//nSplitter的缺省值为5 k:iy()n[  
//default value of nSplitter is 5 W5Jy"]^I  
this("","","",5); ~iiDy;"  
} \(=xc2  
-R1;(n)  
9ghUiBPiL:  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +t*I{X(  
{ YM NLn9  
sSiteURL= sURL; X{i>Q_8>  
sFilePath = sPath; .waj.9&[l  
sFileName = sName; =d<~:!)  
this.nSplitter = nSpiltter; +_vf=d  
#H |p)2k  
ek/zQM@%  
} FYu30  
0*kS\R=P  
XV4aR3n{Q  
public String getSSiteURL() ?li/mc.XG  
{ FqGMHM\J  
return sSiteURL;  Y%y  
} 0t"Iq71/  
~,)D n  
Y=_*Ai  
public void setSSiteURL(String value) l O*  
{ [4bE"u  
sSiteURL = value; &Qj1uf92.  
} ?dv-`)S&  
Wlq3r#  
/zQx}U)TP  
public String getSFilePath() [h&s<<# D  
{ v+trHdSBYE  
return sFilePath; vF~q".imC  
} P|lDW|}D@  
Z-_Xt^N  
]B~ (yh  
public void setSFilePath(String value) 73]t5=D:  
{ }hm_Ws  
sFilePath = value; m J$[X  
} #)48dW!n  
o@[o6.B<  
@;y@Hf'Jv  
public String getSFileName() (~5]1S}F  
{ =b1 y*?  
return sFileName; `)KGajB  
} m#O; 1/P  
m]Qs BK  
PQYJn x}  
public void setSFileName(String value) #uC}IX2n  
{ |f1^&97=+  
sFileName = value; ^'Rs`e  
} SfrM|o  
z?kE((Ey  
pEN`6*  
public int getNSplitter() }vgM$o  
{ M%Vp_ 0  
return nSplitter; hPGDN\#LD  
} >dw 0@T&p  
=`N 0  
=,qY\@fq  
public void setNSplitter(int nCount) lZ2g CZ  
{ 0(Z:QqpU$  
nSplitter = nCount; cG@W o8+  
} \LQZoD?W  
} tux`-F  
#SI]^T|  
k.)YFKi  
/* 2S[:mnK  
**Utility.java M _cm,|FF  
*/ Hv:~)h$  
package NetFox; W>&*.3{v  
u%1JdEWZd  
|DVFi2   
public class Utility { 87)/dHc  
At[SkG}b  
\)aFYDq#\  
public Utility() X2,v'`U5&  
{ cf"!U+x  
j!;E>`g  
ZdPqU \G^q  
} pj3H4yCM:  
yw7bIcs|#b  
//线程睡眠 gF2 93Ez  
public static void sleep(int nSecond) %=s2>vv9  
{ SymlirL  
try{ Wap\J7NY  
Thread.sleep(nSecond); B(eiRr3  
} !Zc#E,  
catch(Exception e) ^)|tf\4  
{ Dd, &a  
e.printStackTrace (); mT|r:Yr:  
} el<[Ng[  
} qM 3(OvCt  
!kh:zTP  
//日志 z`u$C+Ov  
public static void log(String sMsg) u'T>Y1I  
{ ku>Bxau4>  
System.err.println(sMsg); X%;4G^%ZI  
} vYo~36  
Ar_Yl|a  
SF ^$p$mC  
public static void log(int sMsg) Pe11a zJ  
{ 3fYfj  
System.err.println(sMsg); 5;XU6Rz!  
} N?A}WW#  
} q!h'rX=_-  
N!\1O,  
!<X/_+G\  
/* lX 50JJwk  
**TestMethod.java !SLfAFcS  
*/ 2J3y 1  
package NetFox; DD>n-8M@>  
Gsm.a  
!9V; 8g  
public class TestMethod { /7.//klN  
2@N-#x '  
z'gJy  
public TestMethod() HA&hu /mw_  
{ ///xx/weblogic60b2_win.exe 9El{>&Fs4  
try{ :#N]s  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jF#Dc[*  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N~?#Qh|ZnU  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;1r|Bx<5  
fileFetch.start(); yhnPS4DC  
} $g,v]MW  
catch(Exception e){e.printStackTrace ();}  W}Rzn  
52'6wwv6?  
UzV78^:,iD  
} DTdqwe6pi  
diKl}V#u  
n6 c+Okj  
public static void main(String[] args) _@_EQ!=  
{ e Zg>]<L  
new TestMethod(); gmiLjI  
} 7eFFKl  
} x-q_sZ^8  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八