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http断点续传简单实现(java)

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/* C< c6Ub  
**SiteFileFetch.java hSm?Z!+  
*/ z2iMpZ  
package NetFox; (oG YnN,2  
import java.io.*; }PBme'kP  
import java.net.*; ENZym  
c!ZZMC s  
m$p}cok#+S  
public class SiteFileFetch extends Thread { rLsY_7!  
E`o_R=%  
/_0B5 ,6R  
SiteInfoBean siteInfoBean = null; //文件信息Bean iT}>a30]B  
long[] nStartPos; //开始位置 R iLl\S#  
long[] nEndPos; //结束位置 '#7k9\  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 QPVi& *8_  
long nFileLength; //文件长度 N4vcd=uG#  
boolean bFirst = true; //是否第一次取文件 9;+&}:IVS  
boolean bStop = false; //停止标志 h$&Tg_/'#D  
File tmpFile; //文件下载的临时信息 CP J21^  
DataOutputStream output; //输出到文件的输出流 @Chl>s  
`;j1H<L  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) uO]D=Z\S(  
public SiteFileFetch(SiteInfoBean bean) throws IOException ~#E&E%sJ  
{ ,^([aK  
siteInfoBean = bean; },8|9z#pyB  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); NftnbsTmy  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); "z{/*uM2<  
if(tmpFile.exists ()) @P7'MiP]K  
{ (%X *b.n=  
bFirst = false; 1kvX#h&V  
read_nPos(); FOQ-KP\ =,  
} 5-X$"Z|@  
else }|Qh+{H*.  
{ cy8>M))c  
nStartPos = new long[bean.getNSplitter()]; 8J3#(aBm  
nEndPos = new long[bean.getNSplitter()]; "du(BZw  
} m^QoB  
_<(xjWp 8  
2nyK'k  
28"1ONs 3  
} VZi1b0k1.  
 p& _Z}Wv  
JTKS5 r7?  
public void run() 05 6K)E  
{ 5nx*D"  
//获得文件长度 l ms^|?  
//分割文件 i{fw?))+  
//实例FileSplitterFetch =MqEbQn{C3  
//启动FileSplitterFetch线程 D`p2aeI  
//等待子线程返回 RnkV)ed(  
try{ nX!%9x$3  
if(bFirst) hl:Ba2_E +  
{ 4mDHAR%D  
nFileLength = getFileSize(); `j{3|C=  
if(nFileLength == -1) 16 AlmegDk  
{ > SZ95@Oh  
System.err.println("File Length is not known!"); ;5/Se"Nd  
} nGVr\u9z  
else if(nFileLength == -2) SD^::bH  
{ c,r6+oX  
System.err.println("File is not access!"); nOPB*{r|  
} =78y* `L  
else .4a|^ vT  
{ jA,y.(mR  
for(int i=0;i<nStartPos.length;i++) Z?eTjkNS#  
{ NOTG|\{  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); -U2Su|:\N8  
} (]q ([e  
for(int i=0;i<nEndPos.length-1;i++) <#:iltO  
{ oO tjG3B({  
nEndPos = nStartPos[i+1]; &E]) sJ0  
} %Ik5|\ob?  
nEndPos[nEndPos.length-1] = nFileLength; JY c:@\   
} s]m]b#1!r  
} %72# tY  
rPB Ju0D"  
t%mi#Gh(  
//启动子线程 MEI&]qI  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; RhJ3>DL  
for(int i=0;i<nStartPos.length;i++) &3iI\s[  
{ \*MZ 1Q*x  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L"YQji!  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <W!T+sMQj  
nStartPos,nEndPos,i); >7WT4l)7!b  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iX?j"=!  
fileSplitterFetch.start(); .Yk}iHcW.  
} 4M"'B A<  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ue9d0#9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |}77'w :  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", '@24<T]  
nEndPos = " + nFileLength); bD v& ;Z  
// fileSplitterFetch[nPos.length-1].start(); I]HYqI  
Oyb9 ql^  
NkUY_rKPb  
//等待子线程结束 _oZ3n2v}@  
//int count = 0; LiEEQ  
//是否结束while循环 @u+LF]MY  
boolean breakWhile = false; %{ U (y#  
[ (Y@  
|$tF{\  
while(!bStop) .\`M oH  
{ %5L~&W}^"  
write_nPos(); &4wSX{c/P  
Utility.sleep(500); k6 OO\=  
breakWhile = true; E7$ aT^  
}Q[U4G  
T pCXe\W  
for(int i=0;i<nStartPos.length;i++) <DMm [V{  
{ XFFm 'W6@  
if(!fileSplitterFetch.bDownOver) m!INbIh  
{ c @lF*"4  
breakWhile = false; #+i5'p(4  
break; cm!vuoB~~  
} 5bZ0}^FYF  
} di;~$rI!?  
if(breakWhile) Eb,M+c?  
break; kJ* N`=  
eLH=PDdO  
h1'm[Y  
//count++; P{RGW.Ci@  
//if(count>4) 9n5uO[D  
// siteStop(); u$qasII  
} 0 Swu]OE  
<'T DOYb  
(wH+0  
System.err.println("文件下载结束!"); [$6YPM>Ee  
} ,A#gF_8  
catch(Exception e){e.printStackTrace ();} a'q&[08  
} t%y i3  
s4Jy96<  
%f\j)qw  
//获得文件长度 ZXj*Vu$_4  
public long getFileSize() C,O9?t  
{ v)vogtAQa  
int nFileLength = -1; !;t6\Z8&  
try{ (Ms0pm-#t  
URL url = new URL(siteInfoBean.getSSiteURL()); >y!R}`&0^t  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TPj,4&|  
httpConnection.setRequestProperty("User-Agent","NetFox"); FrRUAoF O  
uxX 3wY;M  
-g"Wi@Qr  
int responseCode=httpConnection.getResponseCode(); Vo%ikR #  
if(responseCode>=400) ?:5/4YC  
{ <\d`}A:&  
processErrorCode(responseCode); @]]\r.DG  
return -2; //-2 represent access is error VYK%0S9yH[  
} P-Gp^JX8  
1Fsa}UK  
F)aF.'$-/  
String sHeader;  u7&5t  
z  +c8G  
nWd;XR6|  
for(int i=1;;i++) eS%8WmCV9<  
{ &j"_hFhv  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zq$0 ?vGd  
//Utility.log(in.readLine()); U @}r?!)"f  
sHeader=httpConnection.getHeaderFieldKey(i); T0o0_R  
if(sHeader!=null) }?CKE<#%  
{ 7$Cv=8  
if(sHeader.equals("Content-Length")) Q}^qu6  
{ Tkj F /zv  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *]Eyf")  
break; Lu71Qdu09  
} t#!AfTY$w  
} (2 P&@!|  
else Kciz^)'Z  
break; (s51GRC  
} u`*1OqU  
} S""F58 H n  
catch(IOException e){e.printStackTrace ();} jU{~3Gn?  
catch(Exception e){e.printStackTrace ();} 94lz?-j  
~'Korxa  
US<l4  
Utility.log(nFileLength); r+a0.  
@><8YN^)%  
7Xh ;dJAF3  
return nFileLength; +~xzgaL  
} ,y)V5 c1  
T|--ZRYn  
i@=(Y~tD`  
//保存下载信息(文件指针位置) Xk:_aJ  
private void write_nPos() a!&<jM  
{ 0|mC k  
try{ BtF7P}:MGf  
output = new DataOutputStream(new FileOutputStream(tmpFile)); `nd$6i^#W  
output.writeInt(nStartPos.length); 1#XZVp;M  
for(int i=0;i<nStartPos.length;i++) ddlF4L_  
{ j 9f QV  
// output.writeLong(nPos); "i%=QON`  
output.writeLong(fileSplitterFetch.nStartPos); HC$}KoZkC  
output.writeLong(fileSplitterFetch.nEndPos); A4)TJY 3g  
} 5_rx$avm  
output.close(); /vLW{%  
} b~!Q3o'W  
catch(IOException e){e.printStackTrace ();} @ n$/2y_.  
catch(Exception e){e.printStackTrace ();} 2t3)$\ylQp  
} AD7&-=p&w  
0>3Sn\gZ(  
/9ZU_y4&3f  
//读取保存的下载信息(文件指针位置) ,/eAns`ZU  
private void read_nPos() cZ ,}1?!  
{ Cv< s|  
try{ ^= qL[S6/M  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); M?qvI  
int nCount = input.readInt(); yh+.Yn=+  
nStartPos = new long[nCount]; Y";K WA}b  
nEndPos = new long[nCount]; !!)NER-dv  
for(int i=0;i<nStartPos.length;i++) r:t3Kf`+E-  
{ =BO>Bi&&  
nStartPos = input.readLong(); C:vVFU|4  
nEndPos = input.readLong(); |cl*wFm|3  
} /b."d\  
input.close(); 3oPyh $*  
} `dgZ`#  
catch(IOException e){e.printStackTrace ();} fjqd16{Q  
catch(Exception e){e.printStackTrace ();} O]?PC^GGY  
} !)EYM&:Y  
% 3<7HY]~  
15kkf~Z<t  
private void processErrorCode(int nErrorCode) Pu,2a+0N  
{ 3 t+1M  
System.err.println("Error Code : " + nErrorCode); V?n=yg  
} 7J|nqr`>t  
]4,eCT  
Ime"}*9  
//停止文件下载 PebyH"M(  
public void siteStop() ~Vf A  
{ w u0q.]  
bStop = true; a6"-,Kg  
for(int i=0;i<nStartPos.length;i++) $v1_M1  
fileSplitterFetch.splitterStop(); H ;)B5C  
0\wW%3C  
.i3_D??  
} xC 4L`\  
} m(^nG_eX  
//负责部分文件的抓取 2I_~] X53[  
**FileSplitterFetch.java CTQJ=R"  
*/ ~ L"?C  
package NetFox;  =tc!"{  
)< p ~  
 ^]?ju L  
import java.io.*; bg^ <e}{<H  
import java.net.*; {vp*m :K  
[G"Va_A8  
5Rae?* XH  
public class FileSplitterFetch extends Thread { kTm}VTr 1  
C~04#z_$  
A(+%DZ  
String sURL; //File URL aqv'c j>  
long nStartPos; //File Snippet Start Position [=^Wj`;  
long nEndPos; //File Snippet End Position a2eE!I  
int nThreadID; //Thread's ID ,hE989x<iI  
boolean bDownOver = false; //Downing is over _>4)q=  
boolean bStop = false; //Stop identical U,Fyi6{~  
FileAccessI fileAccessI = null; //File Access interface ^`bMFsP  
c-ql  
EvF[h:C2  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v4, Dt  
{ *$@u`nM  
this.sURL = sURL; Yzw[.(jc}  
this.nStartPos = nStart; JgBC:t^\pV  
this.nEndPos = nEnd; rbrh;\<jM  
nThreadID = id; ?$VkMu$2k  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M<P8u`)>4H  
} :a9   
tN z(s)  
Sv!JA#Ag  
public void run() ==EB\>g|  
{ 4u#TKr.  
while(nStartPos < nEndPos && !bStop) H^M>(kT#&  
{ @I#uv|=N  
P+DIo7VTX  
dj{~!}  
try{ 0!M'z  
URL url = new URL(sURL); >+):eB L  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P=Su)c  
httpConnection.setRequestProperty("User-Agent","NetFox"); z#2n+hwE  
String sProperty = "bytes="+nStartPos+"-";  |^"0bu"  
httpConnection.setRequestProperty("RANGE",sProperty); S:1g(f*85  
Utility.log(sProperty); ,( NN)Oj  
h=B= J  
>~_)2_j  
InputStream input = httpConnection.getInputStream(); - B?c F9  
//logResponseHead(httpConnection); N! I$Qtr,  
R[OXYHu  
L2OR<3*|Av  
byte[] b = new byte[1024]; J M`[|"R%  
int nRead; Rx?ze(  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I moxg+u  
{ my#\(E+  
nStartPos += fileAccessI.write(b,0,nRead); R[@}Lg7+v  
//if(nThreadID == 1) Zpz3 ?VM(  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ilAhw4A  
} d0;?GQYn:  
V)P8w#,  
%< `D' V@  
Utility.log("Thread " + nThreadID + " is over!"); 9dWz3b1[]  
bDownOver = true; `\f 3Ij,  
//nPos = fileAccessI.write (b,0,nRead); 9*r^1PRc  
} cZ#%tT#  
catch(Exception e){e.printStackTrace ();} .eLd0{JtN  
} mv^X{T  
} :[7O=[pk  
l2I%$|)d  
SYa O'c  
//打印回应的头信息 %`YR+J/V  
public void logResponseHead(HttpURLConnection con) [2E(3`-u  
{ h`iOs>  
for(int i=1;;i++) Hz)i.AA 4  
{ u08QE,  
String header=con.getHeaderFieldKey(i); h J0U-m  
if(header!=null) $tej~xZK  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %r8;i  
Utility.log(header+" : "+con.getHeaderField(header)); g/VV2^,  
else <y?=;54a  
break; `evF?t11X  
} &xUD (  
} qHvUBx0  
Sa kew  
J_?v=dW`  
public void splitterStop() :Qh rh(i  
{ b'Km-'MtH  
bStop = true; "p7nngn~  
} U_ l9CZ  
YoBe!-E  
v*%52_   
} ESYF4-d+  
V@[C=K  
{Wu[e,p  
/* n 4y]h  
**FileAccess.java fP\q?X@]E  
*//文件访问(定位,写) 8KYIHw  
package NetFox; 8QoxU" c&  
import java.io.*; x0WinLQ  
gY8$Rk %  
5 7-Hx;  
public class FileAccessI implements Serializable{ *l=(?Pe<  
Eku  9u  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RB|i<`Z  
RandomAccessFile oSavedFile; Wky9w r:g  
long nPos; -$DfnAh  
v; R2,`[W  
xiDgQTDz  
public FileAccessI() throws IOException 8;r#HtFM  
{ *0to,$ n  
this("",0); 4QTHBT+2`  
} ;j7G$s9  
.6xMLo,R  
|<5F08]v  
public FileAccessI(String sName,long nPos) throws IOException U7 ?v4O]D[  
{ ixSr*+  
oSavedFile = new RandomAccessFile(sName,"rw"); =*"8N-FU  
this.nPos = nPos; ]Yw$A  
oSavedFile.seek(nPos); ts9wSx~[+  
} a[ayr$Hk?  
^ nI2<P  
GEA1y^b6"  
public synchronized int write(byte[] b,int nStart,int nLen) g,rmGu3v  
{ _DH^ K 9,9  
int n = -1; gWzslgO6  
try{ RB4 +"QUh  
oSavedFile.write(b,nStart,nLen); _+'!l'`  
n = nLen; -Ep#q&\  
} %,~?;JAj  
catch(IOException e) P_w4 DU  
{ ".N+nM~  
e.printStackTrace ();  ]%FAJ\  
} a4*976~![  
p6R+t]oH  
zX4RqI  
return n; N+@ Ff3M  
} }Sbk qd5  
yDwh]t  
7HBf^N.  
} r9OgezER  
JE7m5k Ta  
f?51sr  
/* dGn 0-l'q  
**SiteInfoBean.java eqsmv [  
*/ j~G(7t  
package NetFox; rpK&OR/  
)N8bO I  
h]s~w  
public class SiteInfoBean { eNK[P=-  
OtmDZ.t;`  
75zU,0"j  
private String sSiteURL; //Site's URL  2Y23!hw  
private String sFilePath; //Saved File's Path |w}j!}u  
private String sFileName; //Saved File's Name dN)8r  
private int nSplitter; //Count of Splited Downloading File T7.Iqw3p  
@$ Zh^+x!  
Z17b=x Jw  
public SiteInfoBean() BZ1wE1t  
{//nSplitter的缺省值为5 5P%#5Yr2  
//default value of nSplitter is 5 d#a/J.Z$A  
this("","","",5); ~x \uZ^:  
} >&KH!:OX|  
9<.O=-1~  
[ gMn  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e;"J,7@  
{  E|"SM A,  
sSiteURL= sURL; KE~Q88s  
sFilePath = sPath; YHQ]]#'  
sFileName = sName; 3HpqMz  
this.nSplitter = nSpiltter; M7cD!s@'I  
i[IFD]Xy!j  
Lo{wTYt:J  
} ,"(G  
)>:~XA|?  
A}(]J!rc  
public String getSSiteURL()  pE)NSZ  
{ Ee2P]4_d  
return sSiteURL; "u!gfG?oH  
} dX cbS<  
QQ.?A(U7  
\+%~7Bi]z  
public void setSSiteURL(String value) ~ p? ArZb  
{ XNWtX-[ ^@  
sSiteURL = value; e^>>" tr  
} ;+E]F8G9r  
'7sf)0\:<p  
PJC(:R(j  
public String getSFilePath() < -`.u`  
{ ,%*UF6B M  
return sFilePath; BX0lk  
} $h{m")]  
:^3) [.m  
;rT'~?q  
public void setSFilePath(String value) Y:ly x-lj  
{ e=OHO,74z"  
sFilePath = value; $lJcC |*  
} /=m AVA  
(yq e 4  
DJ,LQj  
public String getSFileName() i *.Y  
{ sip4,>,E  
return sFileName; UJI2L-;Ul  
} 6MT (k:  
SWV*w[X<X  
U.Mfu9}#:  
public void setSFileName(String value) )OV0YfO   
{ [! $N Tt_  
sFileName = value; Y7}Tuy dC  
} 7z4k5d<^_  
o{sv<$  
xR0T' @q  
public int getNSplitter() -<s Gu9  
{ ^el+ej/=  
return nSplitter; \N*([{X  
} 9E2iZt]  
RVatGa0  
3 }fOb  
public void setNSplitter(int nCount) CLrX!JV>  
{ ?IVJ#6[  
nSplitter = nCount; U"k$qZ[  
} -+rzc&h  
} W\~^*ny P6  
,I jZQ53q~  
qgrJi +WZ  
/* U|} ?{x  
**Utility.java VV$t*9w  
*/ ,/{e%J  
package NetFox; ?uq`|1`  
gm-[x5O"  
WP L@v+  
public class Utility { kcCCa@~v  
^HC 6v;K  
6eV#x%z@v'  
public Utility() EnM  
{ .HS6DOQ  
oFWb.t9<  
t5-O-AI[b{  
} B}iEhWO6  
h 3CA,$HJ  
//线程睡眠 SndR:{  
public static void sleep(int nSecond) )!"fUz$  
{ +-!E% $  
try{ S\A/*!%~y  
Thread.sleep(nSecond); X2|~(*  
} U g"W6`  
catch(Exception e) (I >Ch)'  
{ D@bGJc0  
e.printStackTrace (); 0B`X056|"|  
} tqGrhOt  
} JXB)'d0  
w>%@Ug["  
//日志 wh8';LZ>R  
public static void log(String sMsg) cV+?j}"*+  
{ gg/`{  
System.err.println(sMsg); 4@ PA+(kvS  
} dJ"M#X!Zu  
'#'noB;,  
4V JUu`[  
public static void log(int sMsg) `L'g<VK;  
{ RxP H[7oZ  
System.err.println(sMsg); yix[zfQt0  
} 6zi>Q?] 1  
} <CyU9`ye  
]q]xU,  
AQ~ xjU  
/* G!q[NRu  
**TestMethod.java IO\4dU)  
*/ o:Fq|?/e  
package NetFox; !zA@{gvEc  
oW3"J6,S  
m@Z#  
public class TestMethod { $h#sb4ek  
o`bc/3!  
Og\k5.! ,  
public TestMethod() 9bM\ (s/  
{ ///xx/weblogic60b2_win.exe <Riz!(G  
try{ 5C Dk5B_  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M et]|&  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F$7!j$ Z  
SiteFileFetch fileFetch = new SiteFileFetch(bean); _'=,c"  
fileFetch.start(); >P/36'  
} k#].nQG  
catch(Exception e){e.printStackTrace ();} QZzamT)"  
_ \D %  
w*qj0:i5as  
} =XP[3~  
4zoQe>v~  
'2(m%X\6  
public static void main(String[] args) HlGSt$woX  
{ lzEynMO+  
new TestMethod(); Gw*Tz"  
} {&51@UX  
} /(dP)ysc  
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