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
  • 8268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
/* "&/:"~r  
**SiteFileFetch.java BcaMeb-Z  
*/ t1p}   
package NetFox; )&di c6r  
import java.io.*; LO@.aJpp  
import java.net.*; J<x?bIetj  
I}/o`oc  
lcgT9 m#  
public class SiteFileFetch extends Thread { $Gb] K{e  
7kU:91zR  
!=C4=xv  
SiteInfoBean siteInfoBean = null; //文件信息Bean X1U7$/t  
long[] nStartPos; //开始位置 pq[RH-{  
long[] nEndPos; //结束位置 R? Y#>K  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 <apsG7(7  
long nFileLength; //文件长度 d;&'uiS  
boolean bFirst = true; //是否第一次取文件 U#G[#sd> K  
boolean bStop = false; //停止标志 V-a/%_D  
File tmpFile; //文件下载的临时信息 =W)Fa6P3j(  
DataOutputStream output; //输出到文件的输出流 +7?p& -r)x  
'U]= T<  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) S/-[OA>N  
public SiteFileFetch(SiteInfoBean bean) throws IOException {\22C `9t  
{ _3<J!$]&p  
siteInfoBean = bean; E> Ukxi1  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); m`C(y$8fU  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); QytqO {B^  
if(tmpFile.exists ()) TF 6_4t6  
{ q@;WXHO0  
bFirst = false; `we2zT  
read_nPos(); lZCvH1&"  
} \{J gjd  
else aNb=gjLpt  
{ pH.wCD:1n  
nStartPos = new long[bean.getNSplitter()]; c38RE,4U  
nEndPos = new long[bean.getNSplitter()]; =zXpeo&|m  
} +]H9:ARI  
9 m&"x/k  
|Hg)!5EJ  
eKn&`\j6  
} qgrRH'  
=]E(iR_&  
Z@&_ T3M  
public void run() NylN-X7[#  
{ !zLd ,`  
//获得文件长度 _Hi;Y  
//分割文件 "L.)ML  
//实例FileSplitterFetch 9'3%%o  
//启动FileSplitterFetch线程 QU16X  
//等待子线程返回 )hK5_]"lmj  
try{ t3u"2B7oG  
if(bFirst) ,eOOV@3C  
{ :gDIGBK,  
nFileLength = getFileSize(); r<V]MwO=  
if(nFileLength == -1) Da1BxbDeI  
{ *MW)APw=  
System.err.println("File Length is not known!"); >x@]w sj  
} _z\oDd`'  
else if(nFileLength == -2) 1i#uKKwE  
{ hXM8`iFW5  
System.err.println("File is not access!"); cyA|6Ltg%  
} JV(eHuw  
else 4>>{}c!nf  
{ &#v^y 3r  
for(int i=0;i<nStartPos.length;i++) PXm{GLXRS;  
{ ]B=B@UO@.  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 67%eAS  
} lxj_ (Uo  
for(int i=0;i<nEndPos.length-1;i++) 5+rYk|*D+k  
{ J|_&3@r  
nEndPos = nStartPos[i+1]; A?|KA<&m#u  
} &>0=v  
nEndPos[nEndPos.length-1] = nFileLength; LW?] ~|  
} %75|+((fC  
} 5p"n g8nR  
 dKDtj:  
mm/U9hbp%  
//启动子线程 cy*Td7)/  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h'^7xDw  
for(int i=0;i<nStartPos.length;i++) XV1#/@H;  
{ vi@a87w>  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w_@N T}  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (ZQ{%-i?qR  
nStartPos,nEndPos,i); O^G/(  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kLMg|48fdI  
fileSplitterFetch.start(); dG.s8r*?M  
} '@2pOq  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cKh{ s  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !FipKX  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8U0y86q>)E  
nEndPos = " + nFileLength); "p.MJxH  
// fileSplitterFetch[nPos.length-1].start(); ncb?iJ/b^  
tvP_LNMF  
pA='(G  
//等待子线程结束 !tCw)cou  
//int count = 0; :N\*;>  
//是否结束while循环 '[I_Iu#,  
boolean breakWhile = false; h|yv*1/|  
YZ:YYcr  
eHF#ME  
while(!bStop) yU\&\fD>j  
{ + htTrHjt  
write_nPos(); );@Dr!H  
Utility.sleep(500); )s,L:{<  
breakWhile = true; qW6a|s0}  
e{:P!r aM  
)^ R]3!v  
for(int i=0;i<nStartPos.length;i++) $6XSW  
{ rK)So#'  
if(!fileSplitterFetch.bDownOver) wg^#S  
{ vvv~n ]S6  
breakWhile = false; j;<Yje&Wz  
break; apF!@O^}y  
} cn v4!c0  
} *I`Sc|A  
if(breakWhile) UAnq|NJO  
break; 699z@>$}  
GbwcbfH  
t@ #sKdv  
//count++; \U4O*lq  
//if(count>4) <>A:Oi3^  
// siteStop(); xYc)iH6&  
} oR5hMu;j+  
L^KGY<hp4  
i?z3!`m  
System.err.println("文件下载结束!"); Y]{<IF:  
} =2s 5>Oz+  
catch(Exception e){e.printStackTrace ();} ~7Kqc\/H&I  
} /[VafR!  
Id *Gs>4U  
(;$ J5  
//获得文件长度 ro6|N?'  
public long getFileSize() ] ^to r  
{ 5UVQ48aT  
int nFileLength = -1; sD1L P  
try{ ^uW](2  
URL url = new URL(siteInfoBean.getSSiteURL()); _K )B  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9.qIhg  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;tf1 #6{  
k sJz44  
-TU7GCb=  
int responseCode=httpConnection.getResponseCode(); Cmm"K[>Rx  
if(responseCode>=400) T3[\;ib}  
{ wp-5B= #:{  
processErrorCode(responseCode); 8JAA?0L"'  
return -2; //-2 represent access is error HelC_%#^  
} =5b5d   
FAjO-T4(  
S6B(g_D|  
String sHeader; KwN o/x| v  
;9q3FuR  
_U1~^ucV  
for(int i=1;;i++) }Jk.c~P)  
{ l$z[Vh^UU<  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p>Ju)o  
//Utility.log(in.readLine()); Cnd*%CPZ  
sHeader=httpConnection.getHeaderFieldKey(i); }; +'  
if(sHeader!=null) >MUwT$szs  
{ qBpv[m  
if(sHeader.equals("Content-Length")) "6~pTHT  
{ ]cc4+}L~  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); NZ e3 m  
break; HW|c -\tS  
} 2}'qu)  
} |H2{%!  
else n4 KiC!*i0  
break; /SY40;k:  
} LXVm0IOFF  
} :M`|*~V~$  
catch(IOException e){e.printStackTrace ();} K)]7e?:Wu  
catch(Exception e){e.printStackTrace ();} ;8 JJ#ED  
F4k<YU  
D=mU!rjr1  
Utility.log(nFileLength); Xf:CGR8_  
X;w1@4!  
?Gp~i]  
return nFileLength; -fj;9('YJ  
} ~4U[p  50  
0Q;T <% U  
//JF$o=)D  
//保存下载信息(文件指针位置) F] +t/  
private void write_nPos() ?f1%)]>   
{ 76c4~IG#  
try{ r4gkSwy  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,YSQog  
output.writeInt(nStartPos.length); Fw+JhI VP  
for(int i=0;i<nStartPos.length;i++) @!Il!+^3  
{ 9| v  
// output.writeLong(nPos); fm;1Iu#  
output.writeLong(fileSplitterFetch.nStartPos); Bt Bo%t&  
output.writeLong(fileSplitterFetch.nEndPos); 2 L%d,Ta>  
} C@buewk  
output.close(); j5R= K*y  
} FMwT4]y  
catch(IOException e){e.printStackTrace ();} |^S[Gr w  
catch(Exception e){e.printStackTrace ();} )3.udx  
} !.+iA=K{  
DA]!ndJD  
MCurKT<pQ  
//读取保存的下载信息(文件指针位置) X-3L4@T:?  
private void read_nPos() 1|;WaO1Q  
{ $B~a*zZ7  
try{ Aw4Qm2Kf  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #Q^mdv?  
int nCount = input.readInt(); c500:OSB  
nStartPos = new long[nCount]; _( w4\]  
nEndPos = new long[nCount]; y@~.b^?_u  
for(int i=0;i<nStartPos.length;i++) f4/!iiS}r  
{ \Wt&z,  
nStartPos = input.readLong(); k|BY 7C  
nEndPos = input.readLong(); U> e@m?  
} l2 gI2Cioa  
input.close(); m]Z+u e  
} csRba;Z[  
catch(IOException e){e.printStackTrace ();} 1Lqs>*  
catch(Exception e){e.printStackTrace ();} g|"z'_  
} ?TMo6SU  
T>g1! -^  
MG8-1M  
private void processErrorCode(int nErrorCode) !h?N)9e  
{ y|.wL=;  
System.err.println("Error Code : " + nErrorCode); AW+4Vm_!l  
} mrFMdpaHl%  
hYi-F.Qtq  
QdUl-(  
//停止文件下载 Jfo|/JQ  
public void siteStop() 3`^ ]#Dh  
{ [DGq{(O  
bStop = true; jd]MC*%  
for(int i=0;i<nStartPos.length;i++) tDy1Gh/c  
fileSplitterFetch.splitterStop(); x~Se-#$  
DMfC(w.d  
$T;3*D90  
} ai#EFo+#  
} eFsku8$<  
//负责部分文件的抓取 ut3jIZ1]  
**FileSplitterFetch.java 0AR4/5.  
*/ SkvKzV.R;  
package NetFox; (ter+rTv  
*eUL1m8Y  
F b`V.  
import java.io.*; g=i|D(".  
import java.net.*; xs.[]>nQN  
y,Dfqt  
=xG9a_^v  
public class FileSplitterFetch extends Thread { YH<@->Ip  
Kz$Ijj  
Plm3vk=  
String sURL; //File URL %}'sFu m`  
long nStartPos; //File Snippet Start Position <6v7_  
long nEndPos; //File Snippet End Position `f6Qd2\  
int nThreadID; //Thread's ID | @di<d@  
boolean bDownOver = false; //Downing is over yv$MQ~]  
boolean bStop = false; //Stop identical @ o;m!CYB  
FileAccessI fileAccessI = null; //File Access interface qn+mlduU  
Xk7zXah  
Aqp3amW!  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Bu 6t3  
{ oL VtP  
this.sURL = sURL; *}[@*  
this.nStartPos = nStart; /Zm@.%.  
this.nEndPos = nEnd; 1$xt=*.u|  
nThreadID = id; XZKOBq B]  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ZQ~?  
} 'JkK0a2D  
v'_tna6`O  
N>]u;HjH  
public void run() tH W"eag  
{ |/p ^e  
while(nStartPos < nEndPos && !bStop) n`^</0  
{ ?d_<S0j-)  
gO$!_!@LM  
sM?DNE^BvW  
try{ vW]BOzK  
URL url = new URL(sURL); JBU qZ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _a.Q@A4'  
httpConnection.setRequestProperty("User-Agent","NetFox"); #p_ ~L4iW  
String sProperty = "bytes="+nStartPos+"-"; E )Hp.  
httpConnection.setRequestProperty("RANGE",sProperty); /CX<k gz@  
Utility.log(sProperty); Jwa2Y0  
+x4o#N  
!).D  
InputStream input = httpConnection.getInputStream(); Ay56@_d2  
//logResponseHead(httpConnection); TF{ xFb)  
TcGxm7T  
B*?v`6  
byte[] b = new byte[1024]; $ Q2|{*  
int nRead; -><?q t  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?[T&y ,ln  
{ _N*4 3O`  
nStartPos += fileAccessI.write(b,0,nRead); nR ,j1IUF  
//if(nThreadID == 1) V qYe0-^=P  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y@L`XNl  
} xpSMbX{e  
7v=Nh  
z{tyB  
Utility.log("Thread " + nThreadID + " is over!"); *[ A%tj%  
bDownOver = true; YE0s5bB6  
//nPos = fileAccessI.write (b,0,nRead); f+F /`P%  
} yfaXScbE  
catch(Exception e){e.printStackTrace ();} KU$.m3A>  
} O(!wDnhc  
} }l_) d  
uK t>6DN.  
?)JW}3<.  
//打印回应的头信息 4} =]QQoE  
public void logResponseHead(HttpURLConnection con) kOkgsQQ  
{ 1Z*-@%RX  
for(int i=1;;i++) WE=`8`Li  
{ p-zLi!  
String header=con.getHeaderFieldKey(i); }rOO[,?Y  
if(header!=null) /Nxy?g|,  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #t{?WkO[  
Utility.log(header+" : "+con.getHeaderField(header)); ]Nm_<%lT  
else uTn(fs) D  
break; Bz ]64/  
} ?hmj0i;XC  
} =f{r+'[;^  
W;,Jte<'Nm  
c\-I+lMBi  
public void splitterStop() \O\onvEa  
{ D'A)H  
bStop = true; U3p=H^MB.  
} qzmY]N+w|  
HO$s&}t  
P\w.:.2  
} ~|fd=E%  
|-2,k#|  
Ro? 4tGn  
/* &9TG&~(+  
**FileAccess.java |} .Y&1@U  
*//文件访问(定位,写) '{Iv?gh"  
package NetFox; L?0dZY-"  
import java.io.*; ~ ]o .Mv a  
Qt!l-/flh  
{3`9A7bG  
public class FileAccessI implements Serializable{ ~` #t?1SP  
iB[%5i-  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \6nWt6M  
RandomAccessFile oSavedFile;  #*?5  
long nPos; = V%s^  
t'FY*|xk  
 +loD{  
public FileAccessI() throws IOException EPdR-dC^wE  
{ [o\O^d  
this("",0); \ $z.x-U  
} kS3wa3bT  
 |o=eS&)  
6z!?U:bT  
public FileAccessI(String sName,long nPos) throws IOException JdFMSmZ@  
{ El]Rrku  
oSavedFile = new RandomAccessFile(sName,"rw"); wD}[XE?S  
this.nPos = nPos; [2.pZB  
oSavedFile.seek(nPos); I.1zD aP  
} `'.u$IBW  
EZE/~$`3   
)\'U$  
public synchronized int write(byte[] b,int nStart,int nLen) H2|&  
{ q"`1cFD  
int n = -1; 8H3|^J  
try{ ^|-xmUC  
oSavedFile.write(b,nStart,nLen); ki=-0G*]  
n = nLen; q-X)tH_+w@  
} :C_\.pA  
catch(IOException e) 8%>  Ls  
{ %Mz(G-I.\  
e.printStackTrace (); E(>RmPP=7  
} 7bCTR2e\@w  
d,6 Z  
C3hnX2";  
return n; a]BnHLx  
}  lrU}_`  
ID E3>D  
&ZClv"6  
} T/dchWG  
]aXCi"fMs  
 r,!7TuBl  
/* j'#W)dp(  
**SiteInfoBean.java k 2_ "  
*/  #/MUiV  
package NetFox; Dwe_ytjpc  
w}K<,5I>  
ePP-&V"`"  
public class SiteInfoBean { g\OPidY  
&d[&8V5S  
=YE"6iU  
private String sSiteURL; //Site's URL l;b5v]~  
private String sFilePath; //Saved File's Path K%1'zSAyK  
private String sFileName; //Saved File's Name 7-nwfp&|$  
private int nSplitter; //Count of Splited Downloading File +8 ]}'6m  
GL(R9Y  
tE/j3  
public SiteInfoBean() yOxJx7uD  
{//nSplitter的缺省值为5 ?r"m*fY%  
//default value of nSplitter is 5 K%Vl:2#F  
this("","","",5); g0 \c  
} "|gNNmr  
hIuK s5`  
K)`, |q* \  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &|LZ%W0Fb  
{ Q Bc\=}  
sSiteURL= sURL; wBTnI>l9[  
sFilePath = sPath; P`v%< 9~  
sFileName = sName; q%]0%S?  
this.nSplitter = nSpiltter; _1VtVfiZ{  
d/k&f5  
#6[FGM  
} SuMK=^>%  
,ic.b @u1  
~Yv"=  
public String getSSiteURL() =P!SN]nFeP  
{ MW=2GhD=  
return sSiteURL; n9B1NM5 \  
} N1jj\.nB  
3b (I~  
~vy_~|6s  
public void setSSiteURL(String value) Nc()$Nl8  
{ 1C6H\;  
sSiteURL = value; n{J<7I e"*  
} B8NOPbT  
_'JKPD[  
U-6b><  
public String getSFilePath() mWZoo/xtT  
{ k%?wNk>  
return sFilePath; RcitW;{|Kg  
} ^n"ve2   
`PnB<rf:*1  
-)(HG)3  
public void setSFilePath(String value) i|0H {q  
{ }A'QXtI/G  
sFilePath = value; g!(j.xe  
} ZC'(^liAp  
$/ew'h9q  
v?F~fRH  
public String getSFileName() 5K|1Y#X  
{ yf(VwU, x  
return sFileName; #lRkp.e  
} j4$XAq~W  
% zHsh  
y)X1!3~(  
public void setSFileName(String value) %Ak"d+OH4  
{ );$_|]#  
sFileName = value; l 3bo  
} (dvCejc^p  
}A;J-7g6  
D'2&'7-sm\  
public int getNSplitter() s|.V:%9e  
{ d#cw`h<c~  
return nSplitter; 1nhC! jDD  
} `j{ 5$X  
^noKk6Aaa  
gF+Uj( d  
public void setNSplitter(int nCount) #)QR^ss)iw  
{ 3Z;`n,g  
nSplitter = nCount; %GQPiWu  
} ,rx?Ig}k z  
} J=|PZ2"  
. S4Xw2MS  
*}DCxv  
/* Z_Ffiw(p  
**Utility.java PMC5qQ%x  
*/ s ki'I  
package NetFox; EUevR/S  
%H Pwu &  
]E$h7I  
public class Utility { *o <S{  
MgkeD  
Ey7SQb  
public Utility() 9}LcJ  
{ E0]B=-  
CmKbpN*  
1\K%^<QY  
} }xXUCU<  
mDZ/Kp{  
//线程睡眠 .BP@1K  
public static void sleep(int nSecond) 5nC#<EE  
{ r&6X|2@  
try{ k'Is]=3  
Thread.sleep(nSecond); R"%zmA@o=  
}  1$nlRQi  
catch(Exception e) VrDSN  
{ EY'kIVk  
e.printStackTrace (); eU/o I}A  
} &/o4R:i  
} t&m 8 V$Q  
5DB4vh  
//日志 ((OQs.  
public static void log(String sMsg) 5qZebD2a  
{ Ik W 8$>  
System.err.println(sMsg); (SMnYh4  
} R.nAD{>h*  
PX!$w*q  
^\o3V<  
public static void log(int sMsg) SLI(;, s  
{ R#QOG}  
System.err.println(sMsg); ]k0Pe;<  
} b2rlj6d  
} m/M=.\]  
S)`%clN}J  
%0-fn'  
/* e'"2yA8dh"  
**TestMethod.java ~1xfE C/  
*/ 2H\ }N^;f  
package NetFox; lQ5d.}O&  
sn>2dRW{  
tNk.|}  
public class TestMethod { YCMXF#1  
9x4%M&<Z9a  
hD)'bd  
public TestMethod() }.ZT?p\  
{ ///xx/weblogic60b2_win.exe ML:Zm~A1U  
try{ R%%Uw %`  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X%>n vp  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u4eA++ eT  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3rdrNc  
fileFetch.start(); ab-z 7g  
}  ,>C`|  
catch(Exception e){e.printStackTrace ();} :}B=Bk/q  
P]A~:Lj  
@XJzM]*w&  
} 5I`_S Oa!  
6y0CEly>3#  
o&U'zaj  
public static void main(String[] args) UR{OrNg*  
{ JK jVrx> @  
new TestMethod(); `T#Jiq E  
} &eA!h  
} $*\G Z$y>  
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
批量上传需要先选择文件,再选择上传
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八