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
  • 7882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
/* vnsSy33K  
**SiteFileFetch.java Tx+ p8J|Yr  
*/ ?R?Grw)`H  
package NetFox; r=csi  
import java.io.*; CM 9P"-  
import java.net.*; i>Iee^_(  
7Jx%JgF  
GJak.,0t  
public class SiteFileFetch extends Thread { .)ST[G]WK  
O<`R~  
&telCg:  
SiteInfoBean siteInfoBean = null; //文件信息Bean A^pW]r=Xtk  
long[] nStartPos; //开始位置 Z\!rH "8  
long[] nEndPos; //结束位置 7Dl%UG]  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Kfjryo9  
long nFileLength; //文件长度 ="lI i$>O  
boolean bFirst = true; //是否第一次取文件 8IWw jyRr  
boolean bStop = false; //停止标志 *CUdGI&  
File tmpFile; //文件下载的临时信息 vv h.@f  
DataOutputStream output; //输出到文件的输出流 aYj%w  
XM!M%.0WS  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) h*'d;_(,  
public SiteFileFetch(SiteInfoBean bean) throws IOException } J;~P 9Y  
{ iBHw[X,b  
siteInfoBean = bean; eUs-5 L  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); VG\mo?G  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 6F ;Or  
if(tmpFile.exists ()) LVmY=d>  
{ N*1  
bFirst = false; *tG11gR,&  
read_nPos(); 0#=W#Jl>  
} %^')G+>i  
else 8*)4"rS  
{ Doj(.wm~  
nStartPos = new long[bean.getNSplitter()]; $nFAu}%C  
nEndPos = new long[bean.getNSplitter()]; 6h@+?{F.  
} hNVMz`r  
IozNjII$:.  
thV Tdz  
v$JLDt_  
} E!dp~RwZu  
/hfUPO5  
wi BuEaUkW  
public void run() fM9xy \.  
{ \>;%Ji  
//获得文件长度 &E]"c]i+  
//分割文件 <{ # <5 8  
//实例FileSplitterFetch tj#b_ u z  
//启动FileSplitterFetch线程 [)iN)$Mv  
//等待子线程返回 qzlER  
try{ t[j9R#02?  
if(bFirst) 2$DSBQEx  
{ 5*XH6g F  
nFileLength = getFileSize(); _Ff".t<"  
if(nFileLength == -1) 7?"9J `*  
{ }+JLn%H)  
System.err.println("File Length is not known!"); AgCs;k&IG  
} >.@MR<H#5  
else if(nFileLength == -2) U2=hSzY  
{ %Y 2G  
System.err.println("File is not access!");  0/*X=5  
} q06@SD$   
else 4%>+Wh[  
{ 43F^J%G  
for(int i=0;i<nStartPos.length;i++) :P"9;$FY  
{ :1NYpsd.i  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); DZ%8 |PmB  
} 5IO3 %p?  
for(int i=0;i<nEndPos.length-1;i++) mVHFT~x7}  
{ }Oh5Nm)  
nEndPos = nStartPos[i+1]; K_FBy  
} a^x  0 l  
nEndPos[nEndPos.length-1] = nFileLength; ja:\W\xhJ  
} 5 Af?Yxv  
} v'$ykZ!Z  
uAQg"j  
5Ny0b|+p  
//启动子线程 6<+8}`@B>G  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X; 5S  
for(int i=0;i<nStartPos.length;i++) Ul9b.`6  
{ lkyJ;}_**  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y& m<lnB  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~"\P~cg0J  
nStartPos,nEndPos,i); .;j"+Ef   
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y "<JE<X  
fileSplitterFetch.start(); }Uq/kei^P  
} ![j(o!6&  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;wp W2%&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R<t&F\>  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8db6(Q~P  
nEndPos = " + nFileLength); *eMLbU7  
// fileSplitterFetch[nPos.length-1].start(); `} ZL'\G  
|})rt5|f1!  
ruWye1X;  
//等待子线程结束 bf{Ep=-  
//int count = 0; VgUvD1v?}  
//是否结束while循环 hN!.@L  
boolean breakWhile = false; k:W=5{[  
Us*Vn  
}&=uZ:  
while(!bStop) 1ME|G"$;  
{ ^75pV%<%  
write_nPos(); .!9Vt#  
Utility.sleep(500); "hz>{oe  
breakWhile = true; i^~sn `o  
5N Fq7&rJ6  
e-1;dX HL  
for(int i=0;i<nStartPos.length;i++) g+VRT, r  
{ t% <pbZO  
if(!fileSplitterFetch.bDownOver) 5BZ+b_A>VV  
{ EwC5[bRjUp  
breakWhile = false; }`?7\\6  
break; JHHb|  
} #V,LNX)  
} n&3iz05}  
if(breakWhile) e3G7K8  
break; .`b4h"g:  
q=J9L Q  
T %$2k>  
//count++; @^B S#  
//if(count>4) 2J1B$.3'  
// siteStop(); 5^bh.uF  
} 3KB| NS  
V,`!rJ  
`e4o1 *  
System.err.println("文件下载结束!"); ZE{aS4c  
} dVij <! Lu  
catch(Exception e){e.printStackTrace ();} N;e}dwh&  
} /vMQF+  
jo]m1 2ps  
PV5-^Y"v  
//获得文件长度 &II JKn|_  
public long getFileSize() j0Id!o  
{ S5zpUF=  
int nFileLength = -1; CD*f4I#d  
try{ tj`tLYOZ@-  
URL url = new URL(siteInfoBean.getSSiteURL()); ]:[)KZ~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9<+;hH8J_r  
httpConnection.setRequestProperty("User-Agent","NetFox"); vQ?MM&6  
h2im sjf  
+d|:s  
int responseCode=httpConnection.getResponseCode(); 3Pw %[q=g  
if(responseCode>=400) 9;}L{yve  
{ ~5x4?2  
processErrorCode(responseCode); ~NTDG  
return -2; //-2 represent access is error g/fp45s  
} ly9x1`?$  
m T>b ;  
#JHy[!4  
String sHeader; (jD'+ "?  
cg>!<T*  
k8!hvJ)?  
for(int i=1;;i++) UUt~W  
{ ZJiuj!  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <L[T'ZE+  
//Utility.log(in.readLine()); yBU ZVqqDa  
sHeader=httpConnection.getHeaderFieldKey(i); r@N39O*Wq  
if(sHeader!=null) Q"x`+?!  
{ L{+&z7M  
if(sHeader.equals("Content-Length")) 0(Yh~{   
{ )*q7pO\cty  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &<\4q  
break; IBn'iE[>  
} R!:eYoQ  
} OqAh4qa,$  
else tuL\7 (R  
break;  hg<"Yg=  
} bW,BhUb,|  
} E#IiyZ  
catch(IOException e){e.printStackTrace ();} ?uNTUU,  
catch(Exception e){e.printStackTrace ();} 4i ~eTb  
#`fi2K&]j  
~ z-?rW  
Utility.log(nFileLength); `8$:F4%P  
__oY:d(~  
9b"}CEw  
return nFileLength;  60Xl.  
} "t3uW6&  
bUY:XmA  
,)B~cic'u  
//保存下载信息(文件指针位置) SXT@& @E  
private void write_nPos() UBUB/N Y  
{ ^VM"!O;h{  
try{ o>/uW8  
output = new DataOutputStream(new FileOutputStream(tmpFile)); s= -WB0E  
output.writeInt(nStartPos.length); i} NkHEK  
for(int i=0;i<nStartPos.length;i++) \FY/eQ*07  
{ |IyM"UH  
// output.writeLong(nPos); E.zYi7YUKK  
output.writeLong(fileSplitterFetch.nStartPos); XZUB*P}]D  
output.writeLong(fileSplitterFetch.nEndPos); /h}wM6pg  
} ,u8ZS|9  
output.close(); >S-N|uR6  
} t(uB66(_F  
catch(IOException e){e.printStackTrace ();} S20 nk.x  
catch(Exception e){e.printStackTrace ();} "Gi+zkVm  
} YG}p$\R  
&UJ Ty'  
&k%wOz1vM  
//读取保存的下载信息(文件指针位置) 2ZTyo7P  
private void read_nPos() #Of<1  
{ #2ZrdD"5kQ  
try{ x`j$9XN5  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Eb4< 26A  
int nCount = input.readInt();  Xv? S  
nStartPos = new long[nCount];  HzgQI  
nEndPos = new long[nCount]; ?vL^:f["  
for(int i=0;i<nStartPos.length;i++) \pBYWf  
{ @@&@}IQcR1  
nStartPos = input.readLong(); j:de}!wc  
nEndPos = input.readLong(); it/C y\f  
} ]XpU'/h>q;  
input.close(); H$=h-  
} pDq^W @Rq  
catch(IOException e){e.printStackTrace ();} b3y,4ke"  
catch(Exception e){e.printStackTrace ();} dZ;~b(CA  
} y<'2BTf  
bSeL"   
$Nt]${0  
private void processErrorCode(int nErrorCode) #C=L^cSx(  
{ 2S7H_qo$  
System.err.println("Error Code : " + nErrorCode); m\}\RnZu  
} Ue>A  
>gS5[`xRE  
;k63RNT,M&  
//停止文件下载 ] fwTi(4y  
public void siteStop() pO7{3%  
{ 4/mj"PBKL  
bStop = true; vt(}ga  
for(int i=0;i<nStartPos.length;i++) F_M~!]<na  
fileSplitterFetch.splitterStop(); Xx9~  
~YT>:Np  
(`uC"MLk  
} o<Rxt *B  
} c-3YSrY  
//负责部分文件的抓取 -V<=`e  
**FileSplitterFetch.java =vqE=:X6  
*/ &s6(3k  
package NetFox; 9cw4tqTm  
=Y=^]ayO/  
46.q a nh  
import java.io.*; I;|5C=!  
import java.net.*; EiIFVP   
[&]YVn>kj  
{*5;:QnT  
public class FileSplitterFetch extends Thread { t6,M  
m;tY(kO  
7Hr4yh[j&  
String sURL; //File URL J z:W-o  
long nStartPos; //File Snippet Start Position Y" ]eH{  
long nEndPos; //File Snippet End Position vI:bl~  
int nThreadID; //Thread's ID ,{mf+ 3&$,  
boolean bDownOver = false; //Downing is over w3]0 !) t1  
boolean bStop = false; //Stop identical u_/OTy  
FileAccessI fileAccessI = null; //File Access interface &|&YRHv  
q%=7<( w  
o`y*yucHI  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7$dc? K  
{ LTls]@N  
this.sURL = sURL; nF!_q;+Vp  
this.nStartPos = nStart; W<Vzd4hR  
this.nEndPos = nEnd; w]+BBGYQKb  
nThreadID = id; iYfLo">  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {$QF*j  
} hz~CW-47  
5+Zx-oWq_  
S;AnpiBM8  
public void run() &0<R:K?>N  
{ 7yCx !P;  
while(nStartPos < nEndPos && !bStop) kvO`]>#;$?  
{ %N_S/V0`  
Ll E_{||h  
J/P@m_Yx  
try{ nY5n%>8  
URL url = new URL(sURL); K&a]pL6D  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {]_{BcK+  
httpConnection.setRequestProperty("User-Agent","NetFox"); cI4qgV  
String sProperty = "bytes="+nStartPos+"-"; Z=/L6Zb  
httpConnection.setRequestProperty("RANGE",sProperty); |~" A:gf  
Utility.log(sProperty); .1?i'8TF  
eJ)KE5%n#  
Bc"}nSjH  
InputStream input = httpConnection.getInputStream(); TAXkfj  
//logResponseHead(httpConnection); |9i/)LRXe  
qu~"C,   
LXEu^F~{u#  
byte[] b = new byte[1024]; p$!+2=)gY  
int nRead; s"Pk-Dv  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i\R\bv[9  
{ Ai_|)  
nStartPos += fileAccessI.write(b,0,nRead); q!h*3mNm  
//if(nThreadID == 1) )b2E/G@X&  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hu*>B  
} %IH|zSr)EM  
9oau _Q#  
sT"tS>  
Utility.log("Thread " + nThreadID + " is over!"); D!E 9@*Lf  
bDownOver = true; ]B.,7  
//nPos = fileAccessI.write (b,0,nRead); G`JwAy r'  
} yLa5tv/  
catch(Exception e){e.printStackTrace ();} "E[*rnsLN  
} = ]HJa  
} ZzaW@6LJF  
'  ^L  
hw.demD  
//打印回应的头信息 E?5B>Jer#  
public void logResponseHead(HttpURLConnection con) ;NVTn<Uj  
{ U!UX"r  
for(int i=1;;i++) qx CL  
{ 2dJ)4  
String header=con.getHeaderFieldKey(i); `r0 qn'*  
if(header!=null) n7!Lwq2  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lJQl$Wx^  
Utility.log(header+" : "+con.getHeaderField(header)); 7)It1i-  
else &\D<n; 3  
break; Sw9mrhzJfe  
} G;#t6bk  
} ghd[G}  
U,3K6AZA 7  
5}^08Xl  
public void splitterStop() i@?<]n  
{ D@ 1^:'$V  
bStop = true; H.G^!0j;  
} ia.B@u1/  
[&}<! :9'  
;%.k}R%O@  
} 6!PX! UkF  
bIl0rx[`  
]]QCJf@p  
/* {_N(S]Z  
**FileAccess.java 4)Wzj4qW  
*//文件访问(定位,写) 0+`*8G)  
package NetFox; !Fs) "?  
import java.io.*; zSufU2  
+A3\Hj&W  
^9~%=k=  
public class FileAccessI implements Serializable{ {'bkU9+  
TZ_'nB~  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K]Cs2IpI  
RandomAccessFile oSavedFile; iK0J{'  
long nPos; >bP7}T  
a_MnQ@  
QF6JZQh<  
public FileAccessI() throws IOException pY5HW2TsY|  
{ p" W0$t.  
this("",0); z`{zqP:  
} l]=$<  
EF{'J8AQ  
<g1hdF0  
public FileAccessI(String sName,long nPos) throws IOException /'^>-!8_1  
{ T:5%sN;#O  
oSavedFile = new RandomAccessFile(sName,"rw"); siZ_JJW  
this.nPos = nPos; L. ?dI82c  
oSavedFile.seek(nPos); gx R|S  
} W 9MZ  
m&c(N  
Olh-(u:9+O  
public synchronized int write(byte[] b,int nStart,int nLen) l'8wPmy%N  
{ #mxfU>vQ:  
int n = -1; B>2 1A9&  
try{ QRa6*AYm  
oSavedFile.write(b,nStart,nLen); AQU: 0  
n = nLen; l+qtA~V&2  
} <T[ui  
catch(IOException e) epyYo&x}  
{ ai9,4  
e.printStackTrace (); *%+buHe  
} f=Y9a$.:M  
;P#*R3   
\`# 0,pLr  
return n; HBGA lZ  
} Upen/1bA  
6MQ:C'8T&=  
QP0X8%+p  
} HaUo+,=  
mQuaO# I,  
Qn&^.e9I  
/* z3LPR:&Z  
**SiteInfoBean.java C^O^Jj5X%  
*/ (ZsR=:9(  
package NetFox; HKw4}FC*  
a$& 6a   
<7) 6*u  
public class SiteInfoBean { Lxrn#Z eM  
2 -8:qmP(  
fbkjK`_q  
private String sSiteURL; //Site's URL "b7C0NE  
private String sFilePath; //Saved File's Path IV*$U7~  
private String sFileName; //Saved File's Name b;ZAz  
private int nSplitter; //Count of Splited Downloading File rJj~cPwL"  
z5w|+9U  
.q}k  
public SiteInfoBean() ( "z;Q?(  
{//nSplitter的缺省值为5 8iA(:Tb  
//default value of nSplitter is 5 5nb6k,+E  
this("","","",5); F\72^,0  
} F'*4:WD7  
- mXr6R?  
{m GWMv  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n/D]r  
{ 4tTJE<y  
sSiteURL= sURL; z|H>jit+  
sFilePath = sPath; h]9^bX__Z  
sFileName = sName; Dw,f~D$+ic  
this.nSplitter = nSpiltter; W{aNS@1  
c>.Xc[H  
Lcm!e  
} BT0hx!Ti  
Gjr2]t;E  
2 wvDC@  
public String getSSiteURL() eQj/)@B:V  
{ F tjm@:X  
return sSiteURL; j]SkBZgik  
} ?yK\L-ad  
#1R %7*$i  
gvYs<,:  
public void setSSiteURL(String value) B[50{;X  
{ uD3_'a  
sSiteURL = value; e vuP4-[y  
} =<xbE;,0  
k =_@1b-  
W -&5 v  
public String getSFilePath() _Oq\YQb v  
{ miqCUbcU  
return sFilePath; xM\ApN~W  
} p60D{UzU  
Eq{TZV  
 Pq%cuT%  
public void setSFilePath(String value) { VO4""m  
{ ?Q2pD!L{  
sFilePath = value; RGmpkQEp  
} @Iu-F4YT  
l-EQh*!j  
T(F8z5s5  
public String getSFileName() =ndKG5  
{ ak [)+_k_  
return sFileName; @( l`_Wx  
} ?f&I"\y  
W[s>TDc`v  
EM}z-@A>  
public void setSFileName(String value) 5{Wl(jwb  
{ RkzBn  
sFileName = value; T:$_1I $  
} G]CY3xw98  
^cm^JyS)  
z^.0eP8\j  
public int getNSplitter() y rk#)@/m  
{ flqTx)xE  
return nSplitter; 5@ug1F&   
} wn&2-m*a  
mZyTo/\0  
wQT'~'kL  
public void setNSplitter(int nCount) 6* 7&X#gG  
{ ':3KZ4/C  
nSplitter = nCount; FQ%mNowuj  
} 5FxU=M1gF  
} >.|gmo>b  
m@ YL Z  
r;z A `  
/* 5,C,q%2  
**Utility.java Df (6DuW  
*/ o*_D  
package NetFox; 5mU_S\)4:z  
^>fs  
"L]_NS T  
public class Utility { `Z-`-IL  
j$6}r  
e^yB9b  
public Utility() jxvVp*-=<j  
{ nP^$p C  
HdM;c*K  
tANG ]  
} / <p HDY  
0N.*c  
//线程睡眠 jTnu! H2o  
public static void sleep(int nSecond) /7^~*  
{ -bwl~3ZTi  
try{ OjZ@_V:  
Thread.sleep(nSecond); PW}.`  
} Cp%|Q.?  
catch(Exception e) Ee O{G*pq  
{ W= !f  
e.printStackTrace (); rAKd f??  
} I1g u<a  
} }wV rmDh \  
!T*izMX}  
//日志 9=|5-? ^  
public static void log(String sMsg) !r<7]nwV  
{ lK-I[i!  
System.err.println(sMsg); PO&`r r  
} :"4~VDu  
}MNm>3  
cF6|IlhO  
public static void log(int sMsg) duI8^&|  
{ \cG'3\GI  
System.err.println(sMsg); \1Zf Sc  
} qb Q> z+c  
} )n.peZ  
P]n ' q  
o#i {/# oF  
/* =u(fP" |{  
**TestMethod.java yFSL7`p+  
*/ ^|Y!NHYH$Z  
package NetFox; 5 F-Q&  
U:Y?2$#  
h>wU';5#f  
public class TestMethod { bm;4NA?Gg  
nV,a|V5Xm  
`d8TA#|`  
public TestMethod() +~-|( y  
{ ///xx/weblogic60b2_win.exe DcOLK\  
try{ hXCDlCO  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .NKN2  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [Mi~4b  
SiteFileFetch fileFetch = new SiteFileFetch(bean); mS0W@#|K  
fileFetch.start(); Wh,kJis<  
} gnQd#`  
catch(Exception e){e.printStackTrace ();} STI8[e7{  
>2a~hW|,  
4Xz|HU?  
} _#+i;$cO-X  
'Gk|&^  
W;=ZQ5Lw  
public static void main(String[] args) 7P  
{ <t8})  
new TestMethod(); 2h=RNU|  
} wNlp4Z'[  
} V|7 c dX#H  
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
欢迎提供真实交流,考虑发帖者的感受
认证码:
验证问题:
10+5=?,请输入中文答案:十五