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http断点续传简单实现(java)

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/* $hxN hI  
**SiteFileFetch.java rwIe qV{:  
*/ 80M;4nH^5  
package NetFox; kj5Q\vr)  
import java.io.*; .lhn;*Yi  
import java.net.*; l<(Y_PE:  
~7!7\i,Y8\  
v&FF|)$  
public class SiteFileFetch extends Thread { w#i[_  
97!>%d[0  
z'p:gv]  
SiteInfoBean siteInfoBean = null; //文件信息Bean l8K5k:XCU3  
long[] nStartPos; //开始位置 27ckdyQx  
long[] nEndPos; //结束位置 X}P$emr7  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 >ds%].$-\  
long nFileLength; //文件长度 EliTFxp  
boolean bFirst = true; //是否第一次取文件 Cc?TSZ8[  
boolean bStop = false; //停止标志 clI*7j.4E#  
File tmpFile; //文件下载的临时信息 -)!> M>=s  
DataOutputStream output; //输出到文件的输出流 Ch )dLPz@  
pS4&w8s  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) #<( = }?  
public SiteFileFetch(SiteInfoBean bean) throws IOException eK/?%t  
{ TST4Vy3  
siteInfoBean = bean; (eCFWmO  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ECa$vvK m  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); %=j3jj[  
if(tmpFile.exists ()) -VDo[Zy  
{ nxQ?bk}*d  
bFirst = false; ZWV|# c<G  
read_nPos(); mYB`)M*Y  
} @+U,Nzd  
else H(0q6~|  
{ UkCnqNvx  
nStartPos = new long[bean.getNSplitter()]; N^VD=<#T  
nEndPos = new long[bean.getNSplitter()]; /RLq>#:h**  
} zm9TvoC%}  
CBf7]n0H  
+5v}q.:+  
#$vRJ#S}U  
} x r(|*  
hM@\RPsY  
k&hc m  
public void run() 2Ha5yaTL  
{ +)nT|w45  
//获得文件长度 iV.p5FD  
//分割文件 ~`Qko-a&  
//实例FileSplitterFetch M^rM-{?<  
//启动FileSplitterFetch线程 >95TvJ  
//等待子线程返回 3-40'$lE  
try{ +w| 9x.&W  
if(bFirst) m8+(%>+7  
{ l^NC]t  
nFileLength = getFileSize(); vjViX<#(V  
if(nFileLength == -1) V%HS\<$h  
{  'k&?DZ!  
System.err.println("File Length is not known!"); 7dh1W@\  
} ~$O1`IT  
else if(nFileLength == -2) 'UM!*fk7C  
{ SN+ S6  
System.err.println("File is not access!"); Jeqxspn T  
} @E`?<|B}  
else -jg (GGJ  
{ /7$mxtB5%L  
for(int i=0;i<nStartPos.length;i++) j&6 jRX  
{ &;H{cv`  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); j_?cpm{~ml  
} FgA//)1  
for(int i=0;i<nEndPos.length-1;i++) &A!KJ.  
{ BH0!6Oq  
nEndPos = nStartPos[i+1]; F>|9 52  
} {F*N=pSq  
nEndPos[nEndPos.length-1] = nFileLength; ;Hm'6TR!  
}  Kn+=lCk  
} b`cYpcs  
\9)[ #Ld  
Mj0Cat=  
//启动子线程 ?BCy J  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; MBk"KF  
for(int i=0;i<nStartPos.length;i++) ;'RFo?u K  
{ {j(4m  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eNySJf  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &J"YsY  
nStartPos,nEndPos,i); c|wCKn}`  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EiV=RdL  
fileSplitterFetch.start(); j.-VJo)   
} Rag iV6c  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2?i\@r@E|  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZcPUtun  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n~z\?Y=*  
nEndPos = " + nFileLength); G=M] 8+h  
// fileSplitterFetch[nPos.length-1].start(); !awh*Xj6  
Oo%!>!Lt,  
3 %(Y$8U  
//等待子线程结束 EHf)^]Z  
//int count = 0; sV0Z  
//是否结束while循环 l%"`{   
boolean breakWhile = false; <4F7@q, V  
;:#U 6?=t  
c]Unbm^w  
while(!bStop) {V2bU}5 [  
{ !Cj(A"uqY  
write_nPos(); }6~)bLzI}  
Utility.sleep(500); M1=_^f=&.  
breakWhile = true; zi!#\ s^  
5]"BRn1*  
XK3]AYH  
for(int i=0;i<nStartPos.length;i++) <GWR7rUH  
{ P!+v:'P5f  
if(!fileSplitterFetch.bDownOver) okBE|g  
{ gn5% F5W  
breakWhile = false; oW'PO Ar  
break; {*=E?oF@  
} , p0KLU\-  
} *8!w&ME+.  
if(breakWhile) A|vP$zy  
break; _%IqjJO{=r  
rnvQ<671W  
NXgRNca  
//count++; }z'DWp=uN  
//if(count>4) Tx+ p8J|Yr  
// siteStop(); 4: sl(r  
} { vfq  
(L#%!bd  
1k>naf~O  
System.err.println("文件下载结束!"); gg8c7d:Q  
} GJak.,0t  
catch(Exception e){e.printStackTrace ();} *C_[jk@6  
} 1)U} i ^  
F!CAitxd  
Dr 'sIH^  
//获得文件长度 [,7-w  
public long getFileSize() ('WY5Yps  
{ D9^7m j?e  
int nFileLength = -1; Z\!rH "8  
try{ *( *z|2  
URL url = new URL(siteInfoBean.getSSiteURL()); 7Dl%UG]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <ZrFOb  
httpConnection.setRequestProperty("User-Agent","NetFox"); hPPB45^  
kME^tpji  
*CUdGI&  
int responseCode=httpConnection.getResponseCode(); vv h.@f  
if(responseCode>=400) ;5M<j3_*  
{ b7'F|h^  
processErrorCode(responseCode); *]!l%Uf%  
return -2; //-2 represent access is error } J;~P 9Y  
} iBHw[X,b  
t{ H 1u  
STlPT5e.}  
String sHeader; .YiaXP  
=jUnM> 23  
56ZrCr  
for(int i=1;;i++) jM\ %$_/  
{ DyX0 xx^  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @ KJV1t`  
//Utility.log(in.readLine()); ?>)yKa#U  
sHeader=httpConnection.getHeaderFieldKey(i); /| f[us-w  
if(sHeader!=null) uo 4xnzc  
{ ?waebuj>  
if(sHeader.equals("Content-Length")) ]^ !}*  
{ T&4fBMBp,%  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j)Lo'&Y~=  
break; ;@!;1KDy  
} )d_U)b7i  
} #01/(:7  
else #ko6L3Pi  
break; sy.:T]ZH  
} cKpQr7]ur  
} AY@k-4  
catch(IOException e){e.printStackTrace ();} @H4wHlb  
catch(Exception e){e.printStackTrace ();} kd`YSkZ  
EP0a1.C  
OequU'j  
Utility.log(nFileLength); C M^r|4 K  
>Qk97we'9  
ER2V*,n@  
return nFileLength; ~,G]glu8  
} ?1$\pq^  
HSql)iT  
h/9Sg*k  
//保存下载信息(文件指针位置) 9/Wn!Ld  
private void write_nPos() hOn  
{ h {H]xe[Q  
try{  0/*X=5  
output = new DataOutputStream(new FileOutputStream(tmpFile)); q06@SD$   
output.writeInt(nStartPos.length); 4%>+Wh[  
for(int i=0;i<nStartPos.length;i++) ^@N`e1  
{ `=v@i9cTZ  
// output.writeLong(nPos); DZ%8 |PmB  
output.writeLong(fileSplitterFetch.nStartPos); 5IO3 %p?  
output.writeLong(fileSplitterFetch.nEndPos); _;V YFs  
} .Map   
output.close(); K_FBy  
} a^x  0 l  
catch(IOException e){e.printStackTrace ();} ja:\W\xhJ  
catch(Exception e){e.printStackTrace ();} ME,duY/>Q  
} v'$ykZ!Z  
uAQg"j  
3m~U(yho  
//读取保存的下载信息(文件指针位置) (Y>U6  
private void read_nPos() ) _ #T c  
{ |/t K-c6J  
try{ rSbQ}O4V  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >["Kd.ye  
int nCount = input.readInt(); "|\94  
nStartPos = new long[nCount]; 3} l;  
nEndPos = new long[nCount]; z(r" JNO@  
for(int i=0;i<nStartPos.length;i++) [@zkv)D6  
{ )Jmw|B  
nStartPos = input.readLong(); 8vu2k>  
nEndPos = input.readLong(); vo.EM1x  
} hOV_Oqe4?  
input.close(); eNivlJ,K|@  
} ELD +:b  
catch(IOException e){e.printStackTrace ();} /T{mS7EpYc  
catch(Exception e){e.printStackTrace ();} sbpu qOL  
} ruWye1X;  
w zdxw$E  
VgUvD1v?}  
private void processErrorCode(int nErrorCode) hN!.@L  
{ k:W=5{[  
System.err.println("Error Code : " + nErrorCode); cx<h_  
} vDWr|M%``l  
DU(X,hDBF  
Scf.4~H 0  
//停止文件下载 A03I-^0g+  
public void siteStop() ;Xz(B4N~o  
{ aTi0bQW{  
bStop = true; qP@L(_=g  
for(int i=0;i<nStartPos.length;i++) ~y`Pwj  
fileSplitterFetch.splitterStop(); %jpH:-8'2  
%OTQRe:  
yM W'-\  
} =:kiSrBS3t  
} eO~eu]r  
//负责部分文件的抓取 D_zcOq9  
**FileSplitterFetch.java \gjl^# ;  
*/ Y{`3`Pg&N  
package NetFox; ^9n}-Cqeq  
D~XU `;~u  
N" 8*FiZ|  
import java.io.*; F1zT )wW  
import java.net.*; 3@%BA(M  
hwc:@'  
1mAUEQ!  
public class FileSplitterFetch extends Thread { ]Pz|Oi+]  
uT#Acg  
oXvdR(Sb^  
String sURL; //File URL T<! \B]  
long nStartPos; //File Snippet Start Position 3{6ps : w  
long nEndPos; //File Snippet End Position o$*bm6o  
int nThreadID; //Thread's ID f;&` 9s| 1  
boolean bDownOver = false; //Downing is over Au~+Zz|mQ  
boolean bStop = false; //Stop identical 9T?~$XlX  
FileAccessI fileAccessI = null; //File Access interface wA{*W>i  
r{bgTG  
 ?L`MFR  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jo]m1 2ps  
{ )j$b9ZBk  
this.sURL = sURL; &II JKn|_  
this.nStartPos = nStart; D:+)uX}MOf  
this.nEndPos = nEnd; S5zpUF=  
nThreadID = id; >|y>e{P  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F0X5dv  
} "v*oga%  
Cij$GYkv  
>aNbp  
public void run() U]+b` m  
{ Krt$=:m|1  
while(nStartPos < nEndPos && !bStop) qiF@7i  
{ V.O<|tl.  
"it`X B.  
V,99N'o~x  
try{ k^L#,:\&V  
URL url = new URL(sURL); GLbc/qs  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gsx^j?  
httpConnection.setRequestProperty("User-Agent","NetFox"); =vB]*?;9  
String sProperty = "bytes="+nStartPos+"-"; 3t J=d'U  
httpConnection.setRequestProperty("RANGE",sProperty); b|\{ !N]  
Utility.log(sProperty); a/wUeW  
 m^W*[ ^p  
~N)( ^ 4  
InputStream input = httpConnection.getInputStream(); (MF+/fi  
//logResponseHead(httpConnection); KqT#zj  
W)G2Cs?p  
FN{H\W1cf  
byte[] b = new byte[1024]; xkk@ {}J\  
int nRead; ::^qy^n  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <DA{\'jJ  
{ w !=_  
nStartPos += fileAccessI.write(b,0,nRead); nsM>%+o  
//if(nThreadID == 1) ze#rYNvo/  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'Qp&,xK  
} \}]=?}(  
(:</R$I  
Y3 Pz00x  
Utility.log("Thread " + nThreadID + " is over!"); :pL1F)-*  
bDownOver = true; y\r^\ S9%  
//nPos = fileAccessI.write (b,0,nRead); a+4`}:KA#  
} .b!OZ  
catch(Exception e){e.printStackTrace ();} j\i;'t}8g  
} ox i a}  
} gNMKGf\Y  
^?sSsH z  
HM(bR"E  
//打印回应的头信息 MbT ONt?~v  
public void logResponseHead(HttpURLConnection con) kx;xO>dC  
{ B` t6H  
for(int i=1;;i++) 8gu'dG=  
{ 02]8|B(E90  
String header=con.getHeaderFieldKey(i); PU]7c2.y  
if(header!=null) 5p#o1I  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xr7-[)3Q$  
Utility.log(header+" : "+con.getHeaderField(header)); 8M".o n  
else ue^?/{OuT  
break; 42b=z//;  
} t ?Njw7  
} *Dd(+NI  
y4)ZUv,}  
HlOAo:8'  
public void splitterStop() k=ior  
{ o}r!qL0c  
bStop = true; ~x +:44*  
} eE#81]'6a  
cAsSN.HFS  
S+Y y  
} rS,* s'G  
j:de}!wc  
oJ4mxi@|#  
/* ';fU.uy  
**FileAccess.java dcrJ,>i}  
*//文件访问(定位,写) 0IT20.~  
package NetFox; fmZzBZ_  
import java.io.*; Q9x` Uy  
MZ|c7f&`  
gOES2 4$2  
public class FileAccessI implements Serializable{ g#9*bF  
K\Y6 cj  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rH} Dt@  
RandomAccessFile oSavedFile; 3LmBV\["  
long nPos; n'x`oI)-  
XSHwE)m  
)P(d66yq'u  
public FileAccessI() throws IOException ]VHdE_7)  
{ {8>_,z^P)  
this("",0); iBPdCp%]`  
} bCY^.S-  
.eDxIWW+ft  
1VPN#Q!  
public FileAccessI(String sName,long nPos) throws IOException >FE QtD~F  
{ u}@% 70A  
oSavedFile = new RandomAccessFile(sName,"rw"); c-3YSrY  
this.nPos = nPos; -V<=`e  
oSavedFile.seek(nPos); =vqE=:X6  
} &s6(3k  
k{u%p<  
]( U%1  
public synchronized int write(byte[] b,int nStart,int nLen) oN1wrf}Sh  
{ l66ipgw_^I  
int n = -1; no\}aTx  
try{ ;>QK}#'  
oSavedFile.write(b,nStart,nLen); WkU) I2oH  
n = nLen; Tr}$Pb1  
} 9{]r+z:  
catch(IOException e) ay7+H7^|hZ  
{ "#eNFCo7k  
e.printStackTrace (); W0uM?J\O  
} f'zFg["aZS  
E#HU?<q8  
_>:=<xyOq  
return n; }mT%N eS  
} aBA#\eV  
oRJP5Y5na  
(1r>50Ge  
} ,[K)E  
n9-q5X^e>  
zf!\wY"`  
/* o"+ &^  
**SiteInfoBean.java WY. \<$7  
*/ l.NkS   
package NetFox; {/|8g(  
nD?M;XN  
$0`$)(Y  
public class SiteInfoBean { k~s>8N:&G  
/xm} ?t0U  
K&gc5L  
private String sSiteURL; //Site's URL JXR/K=<^  
private String sFilePath; //Saved File's Path L!}j3(I  
private String sFileName; //Saved File's Name ?\p%Mx?   
private int nSplitter; //Count of Splited Downloading File 2" {]A;@  
!A^w6Q;`V  
2O)Kn q  
public SiteInfoBean() wGQhr="  
{//nSplitter的缺省值为5 yfw>y=/p  
//default value of nSplitter is 5 RT+30Q?  
this("","","",5); hK9oe%kU~  
} >J75T1PH=  
yOCcp+`T}  
4`5Qt=}  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E,yzy[gl  
{ O t4+VbB6  
sSiteURL= sURL; ([XyW{=h!  
sFilePath = sPath; "62Ysapq+  
sFileName = sName; Go+,jT-  
this.nSplitter = nSpiltter; $v}8lBCr3  
ThqfZl=V  
a!J ow?(  
} D(ntVR  
Bw/H'Y  
/dvnQW4}8  
public String getSSiteURL() &+r ;>  
{ 6_}){ZR  
return sSiteURL; :>-sITeY  
} !m O] zn  
[F-u'h< *l  
>p#d;wK4_  
public void setSSiteURL(String value) U@t?jTMBkO  
{ 2D_Vo ])l/  
sSiteURL = value; tS/APSY  
} SIBIh-L  
BHBT=,sI  
f+88R=-u6S  
public String getSFilePath() .$s|T  
{ nF y7gA|  
return sFilePath; xbH!:R;  
} JP% ;rAoJ  
g8qAJ4  
]=XL9MI  
public void setSFilePath(String value) @_:?N(%(  
{ AeQ&V d|  
sFilePath = value; ,xM*hN3A  
} 3'@jRK  
>U Ich  
g:6}zHK  
public String getSFileName() ]X;*\-  
{ L5|;VH  
return sFileName; D@ 1^:'$V  
} cw-JGqLx  
`0vy+T5  
[&}<! :9'  
public void setSFileName(String value) ;%.k}R%O@  
{ 6!PX! UkF  
sFileName = value; bIl0rx[`  
} ]]QCJf@p  
T`0gtSS  
{.8)gVBmA  
public int getNSplitter() -OGy-"  
{ #UnO~IE.m$  
return nSplitter; zSufU2  
} +A3\Hj&W  
szs3x-g  
#Lt+6sa]2@  
public void setNSplitter(int nCount) -hV KPIb  
{ *ww(5 t  
nSplitter = nCount; FrM~6A_  
} cx%9UK*c  
} -r0\  
'Bn_'w~j{  
:hdh$}y  
/* %lW:8 ckL  
**Utility.java l{x#*~g a  
*/ BQmafpp`  
package NetFox; pY5HW2TsY|  
@uD{`@[  
$>37PVVW  
public class Utility { !/9Sb1_~  
!{aA*E{  
<g1hdF0  
public Utility() yFtf~8s3  
{ T:5%sN;#O  
~g|0uO}.  
B{7/A[$%C  
} 5Jd {Ev  
AS^$1i:  
//线程睡眠 /3%xQK>%  
public static void sleep(int nSecond) ~4gKA D  
{ &jd<rs5}  
try{ } ZGpd9D  
Thread.sleep(nSecond); &8L\FAY0%9  
} TTak[e&j3  
catch(Exception e) 3Ya6yz  
{ 'U Cx^-  
e.printStackTrace (); Gf.o{  
} JU+'UK630  
} KftM4SFbK  
Pu*UZcXY  
//日志 |W];v@b\y  
public static void log(String sMsg) X,CF Y  
{ LMj'?SuH  
System.err.println(sMsg); nECf2>Yp v  
} N2Hb19/k  
t O;W?g  
o fv 1G=P  
public static void log(int sMsg) %+J*oFwQu  
{ S*@0%|Q4r  
System.err.println(sMsg); .Sw'Bo!Ee  
} =xP{f<`   
} .Q@'Ob`  
V2skr_1  
?E@[~qq_  
/* "$YLU}S9  
**TestMethod.java =i %w_ e  
*/ RL8 wSK  
package NetFox; ?saVk7Z[|5  
Ka2tr]+s  
SXF_)1QO\W  
public class TestMethod { aBLb i  
L#b Q`t  
ay[*b_f  
public TestMethod() GQWTQIl]  
{ ///xx/weblogic60b2_win.exe "A3xX&9-q  
try{ l_EI7mJ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A2S9h,t  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1yc@q8  
SiteFileFetch fileFetch = new SiteFileFetch(bean); >ON.ftZ i  
fileFetch.start(); &$im^0`r_  
} :N:8O^D^<  
catch(Exception e){e.printStackTrace ();} )S?}huX  
H.K`#W&  
w+P^c|  
} F\72^,0  
 I ^92b  
IbwRb  
public static void main(String[] args) pSUp"wch  
{ VHNiTp  
new TestMethod(); rNp#5[e  
} X|G+N(`|(  
} Ry3 f'gx  
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