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http断点续传简单实现(java)

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/* m0paGG  
**SiteFileFetch.java (:,N?bg  
*/ D`3}j  
package NetFox; vpv PRwJ  
import java.io.*; aN ). G1  
import java.net.*; _MR|(mV  
@za?<G>!'e  
+I/7eIG?|  
public class SiteFileFetch extends Thread { ~d/Doi  
 v#IW;Rj8  
$ Etf'.  
SiteInfoBean siteInfoBean = null; //文件信息Bean #lM!s  
long[] nStartPos; //开始位置 zc'!a"  
long[] nEndPos; //结束位置 )+RGXV p  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 NAZxM9  
long nFileLength; //文件长度 $EN A$  
boolean bFirst = true; //是否第一次取文件 F&lWO!4  
boolean bStop = false; //停止标志 q !7z4Cn  
File tmpFile; //文件下载的临时信息 ORs<<H.d  
DataOutputStream output; //输出到文件的输出流 P}~6 yX  
qdCa]n!d  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ]d9;YVAU  
public SiteFileFetch(SiteInfoBean bean) throws IOException lD6hL8[  
{ oPk2ac  
siteInfoBean = bean; <uU AAHi  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));  ZajQ B  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); AQ32rJT8c`  
if(tmpFile.exists ()) 1jh^-d5  
{ I/|)?  
bFirst = false; ~kS~v  
read_nPos(); r5(OH3  
} `dMOBYV  
else g`y >)N/  
{ }LM^>M%  
nStartPos = new long[bean.getNSplitter()]; KAjKv_6=g  
nEndPos = new long[bean.getNSplitter()]; Fq&@dxN3  
} l|%7)2TyG)  
PD|I3qv~  
Iu 2RK  
q_g'4VZv  
} $T^O38$  
8|dl t$  
_Jj|g9b  
public void run() :V HJD  
{ uB 6`e!Q  
//获得文件长度 tJUMLn?  
//分割文件 U/&?rY^|  
//实例FileSplitterFetch TA`*]*O(  
//启动FileSplitterFetch线程 GTYGm  
//等待子线程返回 D(~6h,=m  
try{ |LcN_ ,}6  
if(bFirst) cwz %LKh  
{ KB&t31aq  
nFileLength = getFileSize(); G( nT.\  
if(nFileLength == -1) LdU, 32  
{ wQ2'%T|t  
System.err.println("File Length is not known!"); y 8];MTl  
} 'hVOK(o 0  
else if(nFileLength == -2) :?RooJ~#  
{ h K@1 s  
System.err.println("File is not access!"); ORv[Gkq_N)  
} er+m:XuV  
else XsQ<ye un  
{ cI?dvfU?  
for(int i=0;i<nStartPos.length;i++) S@Yb)">ZQ  
{ JXftQOn  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ah"2^x  
} UQPd@IVu6  
for(int i=0;i<nEndPos.length-1;i++) aP cO9  
{ $$A{|4,aI  
nEndPos = nStartPos[i+1]; y`mEsj  
} *.Y! ZaK  
nEndPos[nEndPos.length-1] = nFileLength; @xtcjB9  
} L G,XhN  
} =Q.2:*d.  
gEO#-tMjOQ  
l#~Sh3@L(  
//启动子线程 {u9(qd;;  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fF_1ZKx+#!  
for(int i=0;i<nStartPos.length;i++) kkyn>Wxv  
{ V*5:Vt7N  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RT)0I;  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lh7{2WQ  
nStartPos,nEndPos,i); {h&*H[Z z  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yIXM}i:  
fileSplitterFetch.start(); ^(N+s?  
} "0`r]5 5d  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k1$|vzMh  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <Sm =,Sw  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k:m~'r8z  
nEndPos = " + nFileLength); f3y_&I+zl  
// fileSplitterFetch[nPos.length-1].start(); I?4J69'  
V F6OC4 K  
7T_g?!sdMh  
//等待子线程结束 $Fc*^8$ryC  
//int count = 0;  42Gr0+Mb  
//是否结束while循环 qoB   
boolean breakWhile = false; O *H:CW  
MZ=U} &F  
}UXj|SY  
while(!bStop) x@v,qF$K  
{ WB6g i2  
write_nPos(); KT{ <iz_  
Utility.sleep(500); RNRMw;cT  
breakWhile = true; &KbtW_  
M[Y|$I}  
9w11kut-!  
for(int i=0;i<nStartPos.length;i++) *ErTDy(   
{ fS1N(RZ 1  
if(!fileSplitterFetch.bDownOver) y"cK@sOo  
{ `Wn0v2@a(~  
breakWhile = false; Ea!}r| ~]0  
break; #8;^ys1f  
} tI*u"%#t  
} [53@'@26  
if(breakWhile) +]I;C  
break; ujmW {()  
^zs CF0  
`r_qvrC  
//count++; iBN,YPo~  
//if(count>4) 9^v|~f  
// siteStop(); lH:TE=|4  
} Z:O24{ro5  
BB--UM{7  
%lv2;-  
System.err.println("文件下载结束!"); JF: QQ\  
} cp0>Euco=  
catch(Exception e){e.printStackTrace ();} ~M(K{6R  
} [xO^\oQa=c  
`q7I;w+g  
9@QP?=\Y  
//获得文件长度 ;NLL?6~  
public long getFileSize() L9fhe,en  
{ <g>_#fz"K  
int nFileLength = -1; 2?Q IK3"v  
try{ # Sb1oLC  
URL url = new URL(siteInfoBean.getSSiteURL()); *3S,XMS{O  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (G#)[0<fX  
httpConnection.setRequestProperty("User-Agent","NetFox"); lk6mu  
<~"qz*_  
p'KU!I }  
int responseCode=httpConnection.getResponseCode(); <%>Q$b5  
if(responseCode>=400) 9m!4U2N,s  
{ Y&Pi`E9=  
processErrorCode(responseCode); u\Fq\_  
return -2; //-2 represent access is error _m3PAD4  
} OjJlGElw  
(mt,:hX  
[g=yuVXNZZ  
String sHeader; fU>"d>6!S  
$o/ ?R]h  
Z=8 25[p  
for(int i=1;;i++) ;]Y.2 J  
{ ZS>}NN  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); m[ay  
//Utility.log(in.readLine()); K`(STvtM  
sHeader=httpConnection.getHeaderFieldKey(i); d!G%n *  
if(sHeader!=null) NjYpNd?g  
{ eW\7X%I  
if(sHeader.equals("Content-Length")) ll[U-v{  
{ KDRIy@[e  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VH#]67  
break; rm2{PV<+d  
} OPwp(b  
} lsJ'dS  
else tz1iabZ{  
break; .Ks&r  
} \w^U<_zq  
} qa`bR%eH  
catch(IOException e){e.printStackTrace ();} oIoJBn  
catch(Exception e){e.printStackTrace ();} Iimz  
f*W<N06EZ  
l:j9lBS  
Utility.log(nFileLength); [ {lF1+];@  
{s=QwZdR  
d?b2jZ$r]  
return nFileLength; )l[ +7  
} UbY-)9==  
JY9Hqf  
q/70fR7{v  
//保存下载信息(文件指针位置) j#-ZL-N  
private void write_nPos() -a&wOn-W  
{  <gf:QX!  
try{ ?v8RY,Q30  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~}8 3\LI}  
output.writeInt(nStartPos.length); 9zi/z_G  
for(int i=0;i<nStartPos.length;i++) r'{pTgm#  
{ kRSu6r9  
// output.writeLong(nPos); 'PV,c|f>  
output.writeLong(fileSplitterFetch.nStartPos); JS({au  
output.writeLong(fileSplitterFetch.nEndPos); P0' ;65  
} KkJcH U  
output.close(); v SHb\V#  
} &Vnet7LfU  
catch(IOException e){e.printStackTrace ();} Qs#v/r  
catch(Exception e){e.printStackTrace ();} ^a<=@0|  
} WAqR70{KM  
isWB)$q  
'e;*V$+  
//读取保存的下载信息(文件指针位置) [A*vl9=  
private void read_nPos() 7lR(6ka&/  
{ P1Re7/  
try{ 47`{ e_YP0  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t!D=oBCro  
int nCount = input.readInt(); fm&l 0  
nStartPos = new long[nCount]; !G`w@E9M)  
nEndPos = new long[nCount]; 2ZIf@C{P.  
for(int i=0;i<nStartPos.length;i++) .Zf#L'Rf  
{ 8N ci1o  
nStartPos = input.readLong(); ` mALx! `  
nEndPos = input.readLong(); w V2 7  
} 6tzZ j:y q  
input.close(); Ujq)h:`  
} FE/&<g0,:  
catch(IOException e){e.printStackTrace ();} ;S,g&%N  
catch(Exception e){e.printStackTrace ();} W%0-SR  
} '~liDz*O   
\ {"8(ELX  
kJJQcjAP:  
private void processErrorCode(int nErrorCode) W=I%3F_C"R  
{ oUltr  
System.err.println("Error Code : " + nErrorCode); :T%,.sH  
} n9cWvy&f  
-}4H'%Z(i  
$dorE ~T  
//停止文件下载 +-qD!(&-6  
public void siteStop() '~3( s?B  
{ N|1J@"H  
bStop = true;  78qf  
for(int i=0;i<nStartPos.length;i++) LP=!u~?  
fileSplitterFetch.splitterStop(); =E4nNL?  
3,N7Nfe  
OK3B6T5w=  
} wT*`Od8w  
} K# _plpr  
//负责部分文件的抓取 z_A%>E4  
**FileSplitterFetch.java WYEvW<Hv  
*/ 3i35F.=X,  
package NetFox; ^]E| >~\  
,A[HYc|uy  
]vKxgfF  
import java.io.*; .u W_(Rqg  
import java.net.*; gj6"U {D  
yMX4 f  
%4n=qK9T 5  
public class FileSplitterFetch extends Thread { Z PZ1 7-  
[r^f5;Z  
#?}Y~Oe  
String sURL; //File URL Y$oBsg\v  
long nStartPos; //File Snippet Start Position 8ne5 B4  
long nEndPos; //File Snippet End Position 6\~m{@  
int nThreadID; //Thread's ID oY+RG|j@  
boolean bDownOver = false; //Downing is over A{&Etu(K  
boolean bStop = false; //Stop identical b*P \a  
FileAccessI fileAccessI = null; //File Access interface \f /<#'  
6"&&s  
d{ OY  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Z;WqKIM#  
{ nqiy)ZN#R  
this.sURL = sURL; Y*w< ~m  
this.nStartPos = nStart; -pg7>vOq  
this.nEndPos = nEnd; P 3lN ns3  
nThreadID = id; 4fP>;9[F  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r10)1`[  
} mN@0lfk;  
Z(xn-  
V :d/;~  
public void run() hDmVv;M:  
{ &,NHk9.aq  
while(nStartPos < nEndPos && !bStop) YdC:P# Nf  
{ J0o U5d=3  
_ogT(uYyr  
60X B  
try{ ^+,mxV'8!  
URL url = new URL(sURL); #i)h0ML/e  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :,GsbNKW  
httpConnection.setRequestProperty("User-Agent","NetFox"); nM R _ ?g  
String sProperty = "bytes="+nStartPos+"-"; !aLByMA  
httpConnection.setRequestProperty("RANGE",sProperty); \ZCc~muR  
Utility.log(sProperty); $t}L|"=8X  
ap;*qiNFQ  
i$%;z~#wW  
InputStream input = httpConnection.getInputStream(); 7J$ ^R6rh  
//logResponseHead(httpConnection); pjbKMx  
_|*3uGo:  
U$0#j  
byte[] b = new byte[1024]; __3Cjo^6&  
int nRead; @["Vzg!I6"  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z)6bqU<LQE  
{ D }b+#G(m[  
nStartPos += fileAccessI.write(b,0,nRead); {/#?n["  
//if(nThreadID == 1) atl0#FBd  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &y Vii^  
} ;'=!Fv  
K})j5CJ/  
{yspNyOx  
Utility.log("Thread " + nThreadID + " is over!"); /\#qz.c2K  
bDownOver = true; N;Hf7K  
//nPos = fileAccessI.write (b,0,nRead); %v}:#_va]  
} .HGEddcC  
catch(Exception e){e.printStackTrace ();} hQ<"  
} w9.r`_-  
} Zu~ #d)l3N  
puMpUY  
';b/D   
//打印回应的头信息 (qB$I\  
public void logResponseHead(HttpURLConnection con) QdDdrR^&  
{ 8i X?4qj{P  
for(int i=1;;i++) N15{7 ,   
{ 1s!hl{n<~  
String header=con.getHeaderFieldKey(i); C(W?)6?  
if(header!=null) IybMO5Mwn  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yKfRwO[ j  
Utility.log(header+" : "+con.getHeaderField(header)); ;=UrIA@y;=  
else W P.6ea7k  
break; 4(B,aU>y  
} 2psI\7UjA]  
} m$[ \(Z(/  
Fnll&TF  
|q5\1}@:  
public void splitterStop() ??1V__w  
{ TS=p8@w}  
bStop = true; 6Y}#vZ  
} 2psLX  
,F:l?dfB\I  
oVmGZhkA@'  
} |y;+xEl6  
"d.qmM  
! daXF&q  
/* NGS/lKz  
**FileAccess.java %)q5hB  
*//文件访问(定位,写) b/O~f8t  
package NetFox; ;Iv)J|*  
import java.io.*; 7i 6-Hq  
UyK|KL  
/=Q7RJ@P  
public class FileAccessI implements Serializable{ k[G?22t  
m_(+-G  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WW==  
RandomAccessFile oSavedFile; =xa`)#4(  
long nPos; \[Rh\v&  
cB?HMLbG>  
 >cSc   
public FileAccessI() throws IOException Dc BTW+  
{ PiAA,  
this("",0); Ij{{Z;o3  
} WERK JA  
rxm!'.+  
vco:6Ab$  
public FileAccessI(String sName,long nPos) throws IOException )v ['p  
{ uCUQxFp  
oSavedFile = new RandomAccessFile(sName,"rw"); ?~u"w OH'  
this.nPos = nPos; MdEZ839J  
oSavedFile.seek(nPos); X g.\B1d  
} r7w&p.?  
>Qt#6X|  
mC J/gWDY  
public synchronized int write(byte[] b,int nStart,int nLen) =_Qt&B)  
{ WR~uy|mX  
int n = -1; G%rK{h  
try{ =%$ _)=}J  
oSavedFile.write(b,nStart,nLen); 52-^HV  
n = nLen; W%~ S~wx  
} VA2%2g2n{  
catch(IOException e) xE4T\%-K  
{ g-')|0py  
e.printStackTrace (); =_L"x~0I-  
} 1Qf5H!5vx  
Mgf80r=  
&)\0mpLK9  
return n; JJ7-$h'0q  
} QD / | zi  
MLa]s* ; d  
eFZ`0V0  
} !|Vjv}UO  
u%h]k ,(E  
|h6)p;`gc  
/* f N t  
**SiteInfoBean.java rmWG9&coW  
*/ B8[H><)o\y  
package NetFox; jC; XY!d6  
^$rt|]  
1N:eM/a  
public class SiteInfoBean { d![EnkyL;  
@@!t$dD  
)"j_ NlO  
private String sSiteURL; //Site's URL TKj9s'/  
private String sFilePath; //Saved File's Path % J+'7'g  
private String sFileName; //Saved File's Name ^R K[-tVV  
private int nSplitter; //Count of Splited Downloading File 3H4p$\; C  
+J.^JXyp0  
5l{_E:.1  
public SiteInfoBean() 51&wH  
{//nSplitter的缺省值为5 8kO|t!?:U  
//default value of nSplitter is 5 b4,yLVi<T  
this("","","",5); tEf-BV;\y  
} 2R|2yAh  
0/-[k  
R,6?1Z:J  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) HHg=:>L z  
{ MZ% P(5  
sSiteURL= sURL; qK(? \ t$  
sFilePath = sPath; S }fIZ1  
sFileName = sName; t {x&|%u  
this.nSplitter = nSpiltter; M{hA`  
'4N[bRCn  
 (lt/ t  
} U/{cYX  
)RA7Y}e|m  
]+fL6"OD/2  
public String getSSiteURL() ){8^l0b  
{ %H%>6z x  
return sSiteURL; ^H&6'A`  
} ]9b*!n<z  
H( cY=d,  
#?8'Z/1 )  
public void setSSiteURL(String value) [.3M>,)+-  
{ OP``g/x)  
sSiteURL = value; :5C9uW #  
} GT#iY*  
MF%9  
IjNE1b$  
public String getSFilePath() \kC/)d  
{ ]FsPlxk6  
return sFilePath; 1/ j}VC  
} ~e'FPVDn  
Eepy%-\  
-C.eXR{s  
public void setSFilePath(String value) $yc&f(Tv  
{ ^\Jg {9a  
sFilePath = value; F<G.!Y8!&  
} z[CCgs&vqe  
`[CXxp  
IvH0sS`F  
public String getSFileName() MPNBA1s  
{ bha_bj  
return sFileName; ~Dgui/r9J  
} Sh{odrMj*  
|)GE7y0Q  
=p^*y-z  
public void setSFileName(String value) 2nOQ48ha T  
{ RwY) O5  
sFileName = value; &eg]8kV  
} rK)%n!Z  
S(/@.gI:f  
*|hICTWL  
public int getNSplitter() \XmtSfFC  
{ MqXA8D  
return nSplitter; %~$4[,=  
} D|_}~T>;&  
DF9Br D0{  
p2w/jJMD  
public void setNSplitter(int nCount) GawLQst[+  
{ ZLo3 0*  
nSplitter = nCount; sveFxI  
} tA'i-D&  
} <>2QDI6_  
ezHj?@  
N b(se*Y#  
/* B/pNM81(  
**Utility.java G}] ZZ  
*/ evtn/.kDR  
package NetFox; +h*&r ~T  
0^{zq|%Q!  
M!mTNIj8~  
public class Utility { A5 8i}G9  
z?FZu,h}  
`p'L3u5H-  
public Utility() Y5Ey%M m6  
{ m,]Tl;f  
*)u_m h  
@{XN}tWDOp  
} (7-K4j`   
QAcvv 0Hv  
//线程睡眠 #`}g?6VHo  
public static void sleep(int nSecond) P,tN;c  
{ $?I ^Dk  
try{ 9$S2:2(G  
Thread.sleep(nSecond); [yjC@docH  
} iY.~N#Q  
catch(Exception e) `M"b L|[R  
{ "eGS~-DVK  
e.printStackTrace (); p7 2+:I  
} E/AM<eN  
} }{E//o:Ta  
[xM07%:  
//日志 SLZv`  
public static void log(String sMsg) %l3RM*zb  
{ ?mgr #UN  
System.err.println(sMsg); kZF\V7k  
} {TUCa  
{`l]RIig  
I caIB)  
public static void log(int sMsg) f{^n<\Jh  
{ ^!Bpev  
System.err.println(sMsg); ,gD30Pylz  
} mX,#|qLf  
} } vcr71u  
ZOS{F_2.  
5p"*n kF  
/* t41\nTZr  
**TestMethod.java ki}Uw#  
*/ G|Q}.v  
package NetFox; F-_RL-hbN%  
Rp.@  
Ia>qVM0  
public class TestMethod { ^JY R^X>_  
t}NxD`8  
& }k=V4L  
public TestMethod() l\MiG Na  
{ ///xx/weblogic60b2_win.exe F KL}6W:  
try{ "D@m/l  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .[K{;^>  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9HP)@66  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Oi l>bv8  
fileFetch.start(); l  4~'CLi  
} MY1 tYO  
catch(Exception e){e.printStackTrace ();} u'?t'I  
9chiu%20  
AS4m227  
} a$;+-Y  
:gQc@)jZ(*  
kl2]#G(  
public static void main(String[] args) x40R)Led  
{ Mzxz-cE  
new TestMethod(); MZ0uc2L=  
} 0r+-}5aSl5  
} d7KeJ$xy}p  
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