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http断点续传简单实现(java)

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/* r1:CHIwK  
**SiteFileFetch.java 3S" /l  
*/ ,B'fOJ.2  
package NetFox; .y<u+)  
import java.io.*; |}b~YHTs  
import java.net.*; 7}vI/?r  
-iL:D<!Cb_  
<~P!yLr  
public class SiteFileFetch extends Thread { %OOkPda  
KD.|oo  
3g3f87[  
SiteInfoBean siteInfoBean = null; //文件信息Bean W/g_XQ   
long[] nStartPos; //开始位置 M.+h3<%^  
long[] nEndPos; //结束位置 dz!m8D0  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 zl( o/n  
long nFileLength; //文件长度 5XV|*O;  
boolean bFirst = true; //是否第一次取文件 -Nn< pq  
boolean bStop = false; //停止标志 eph2&)D}Ep  
File tmpFile; //文件下载的临时信息 <cU%yA710  
DataOutputStream output; //输出到文件的输出流 Tl2(%qB  
"c\WZB`|  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 5?Pf#kq  
public SiteFileFetch(SiteInfoBean bean) throws IOException QiK-|hFj  
{ F?[1 m2  
siteInfoBean = bean; !o1IpTN  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 83 <CDjD  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); HQ]mDo  
if(tmpFile.exists ()) c0Pj})-  
{ 05g %5vHF  
bFirst = false; @dx 8{oQ  
read_nPos(); $JUkw sc  
} ka6E s~  
else x-]:g&5T  
{ t+_\^Oa)  
nStartPos = new long[bean.getNSplitter()]; <ZheWl  
nEndPos = new long[bean.getNSplitter()]; hz*T"HJ]t  
} 6l[ v3l"t  
`So/G  
+(PUiiP'"v  
h8X[*Wme  
} XwFTAaZ  
.]s? 01Z  
b $yIM  
public void run() -DK6(<:0  
{ %P D}VF/Y  
//获得文件长度 uVKe?~RC  
//分割文件 9!FU,4 X  
//实例FileSplitterFetch KJ:z\N8eo  
//启动FileSplitterFetch线程 yjsj+K pL  
//等待子线程返回 "{\xBX~oM  
try{ {Wi*B(  
if(bFirst) 7'"qW"<  
{ ptrwZ8'  
nFileLength = getFileSize(); FvY=!U06  
if(nFileLength == -1) k1oJ<$ Q  
{ DP0@x+`k  
System.err.println("File Length is not known!"); _GFh+eS}  
} ~M8|r!_  
else if(nFileLength == -2) Cf9{lhE8  
{ 6 &0r/r  
System.err.println("File is not access!"); E*`PD<:)H  
} 0G6aF"  
else /(*Ucv2i}T  
{ Wy}^5]R0E  
for(int i=0;i<nStartPos.length;i++) 3E^qh03(  
{ }79O[&  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 2Z%n "z68  
} -gm5E qi  
for(int i=0;i<nEndPos.length-1;i++) -fXQ62:S  
{ xT]t3'y|-  
nEndPos = nStartPos[i+1]; yo/;@}g}  
} /]^Y\U^  
nEndPos[nEndPos.length-1] = nFileLength; ^C1LQ Z  
} ge(,>xB  
} 8lzoiA_9  
`g3AM%3  
!Ve0:$  
//启动子线程 LRts W(A/  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; qB (Pqv  
for(int i=0;i<nStartPos.length;i++) #>("(euXMF  
{ LWm1j:0  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bm 4RRI  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y!_{:2H8p  
nStartPos,nEndPos,i); IdN3Ea]  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); / Ws>;0  
fileSplitterFetch.start(); 0&j90J$`  
} 7P<f(@0h$E  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /'aqQ K<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (Hj[9[=  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;Mo_B9  
nEndPos = " + nFileLength); ge1. HG  
// fileSplitterFetch[nPos.length-1].start(); \*=wm$p&*  
9?MzIt  
J@2wPKh?Yp  
//等待子线程结束 "3\y~<8%'  
//int count = 0; ||>4XDV#  
//是否结束while循环 hNsi  8/  
boolean breakWhile = false; w2UEU5%  
*U,J Q  
`_)H aF>/  
while(!bStop) vQyY %  
{ Vx2/^MiXy  
write_nPos(); JPAjOcmU/  
Utility.sleep(500); g i6s+2  
breakWhile = true; fs 2MYat  
l=p_  
5{k,/Z[L  
for(int i=0;i<nStartPos.length;i++) 'E9{qPLk(  
{ x<M::")5!V  
if(!fileSplitterFetch.bDownOver) wpuK?fP  
{ 6ICW>#fI`  
breakWhile = false; \OtreYi  
break; 'mbLK#q  
} o+&Om~W  
} JR#4{P@A  
if(breakWhile) ,wes*  
break; #55:qc>m  
<O 0Q]`i  
V%s7*`U  
//count++; (87| :{  
//if(count>4) ~Ym _ {  
// siteStop(); $uDgBZA\  
} p$9Aadi]  
/ Qd` ?  
6vsA8u(|V#  
System.err.println("文件下载结束!"); eZAMV/]jH  
} A~PR  
catch(Exception e){e.printStackTrace ();} TT/H"Ri}Jp  
} tngB;9c+w  
QF/_?Tm4  
zP%s]>hH  
//获得文件长度 Z8ea)_ {#  
public long getFileSize() \hgd&H0UU  
{ P0}{xq'k9v  
int nFileLength = -1; 9>w~B|/  
try{ 3\@2!:>  
URL url = new URL(siteInfoBean.getSSiteURL()); &Y?t  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); olv?$]  
httpConnection.setRequestProperty("User-Agent","NetFox"); iW(LD1~7  
`!Z?F]):G  
HvG %##  
int responseCode=httpConnection.getResponseCode(); u_$4xNmQ  
if(responseCode>=400) dEtjcId  
{ ;6P>S4`w  
processErrorCode(responseCode); hg" i;I  
return -2; //-2 represent access is error ]"Uzn  
} (T#$0RFq  
qisvGHo  
Q}@t'  
String sHeader; xyL)'C  
B#S8j18M  
0fXMY-$I  
for(int i=1;;i++) NUYKMo1ze  
{ G-T^1?  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); * ) <+u~  
//Utility.log(in.readLine()); 8F8?1  
sHeader=httpConnection.getHeaderFieldKey(i); S[3"?$3S  
if(sHeader!=null) ,~naKd.ZY  
{ e9{0hw7  
if(sHeader.equals("Content-Length")) dgpE3 37Lt  
{ !2KQi=Ng  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); PiKP.  
break; o@zxzZWg  
} 6]b"n'G  
} aNEah  
else uKP4ur@1  
break; FSA%,b; U  
} \uOM,98xS  
} uVn"L:_  
catch(IOException e){e.printStackTrace ();} Ah wi  
catch(Exception e){e.printStackTrace ();} RH;ulAD6(~  
\s&Mz;:  
nUP, Yd  
Utility.log(nFileLength); d=xjLbsZ  
^7spXfSAd  
a{T.U-0   
return nFileLength; 7x6 M]1F  
} adP  :{j  
(0NffM1  
mp8GHV  
//保存下载信息(文件指针位置) "5V;~}=S  
private void write_nPos() 60!%^O =  
{ jG[Vp b  
try{ 6/8K2_UeoW  
output = new DataOutputStream(new FileOutputStream(tmpFile)); \~hrS/$[$  
output.writeInt(nStartPos.length); PK2;Ywk`  
for(int i=0;i<nStartPos.length;i++) 6h>#;M  
{ 5U~KYy^v  
// output.writeLong(nPos); hi[nUG(OI  
output.writeLong(fileSplitterFetch.nStartPos); %, psUOY  
output.writeLong(fileSplitterFetch.nEndPos); +-@n}xb@  
} =Pl@+RgK+  
output.close(); 2nkA%^tR  
} FYYc+6n  
catch(IOException e){e.printStackTrace ();} T%eBgseS  
catch(Exception e){e.printStackTrace ();} JI-i7P  
} cpjwc@UMe  
H:c5 q0O^x  
9i5?J]o^  
//读取保存的下载信息(文件指针位置) UUV5uDe>i  
private void read_nPos() F<I*?${[  
{ ;98&5X\u<  
try{ [nO3%7t@  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $K^l=X  
int nCount = input.readInt(); #h[>RtP:  
nStartPos = new long[nCount]; (I}owr5:  
nEndPos = new long[nCount]; OZxJDg  
for(int i=0;i<nStartPos.length;i++) * hs&^G  
{ 0A) 0Zw  
nStartPos = input.readLong(); ,>-D xS  
nEndPos = input.readLong(); oFU:]+.+D  
} TWpw/osW  
input.close(); = J;I5:J  
} x 7by|G(  
catch(IOException e){e.printStackTrace ();} z{L'7  
catch(Exception e){e.printStackTrace ();} MV"n{1B  
} d%8n   
d-~V.  
srv4kodj  
private void processErrorCode(int nErrorCode) 44ty,M3  
{ _X4Y1zh  
System.err.println("Error Code : " + nErrorCode); S $p>sItO  
} 1jg* DQ7L  
4,sE{%vb  
fY00  
//停止文件下载 wb.yGfJ  
public void siteStop() _aFe9+y  
{ Mr)t>4  
bStop = true; h=A  
for(int i=0;i<nStartPos.length;i++) "b hK %N;  
fileSplitterFetch.splitterStop(); Nnh\FaI  
[K3 te  
|c/=9Bb  
} z{W C w  
} u4Nh_x8\Nr  
//负责部分文件的抓取 @Y/&qpo$#W  
**FileSplitterFetch.java UT\4Xk<  
*/ /yG7!k]Eg  
package NetFox; OeqKKVuQ  
inGUN??  
. }\8Y=  
import java.io.*; f`hZb  
import java.net.*; =VD],R)  
>_2~uF@pb  
;TJpD0  
public class FileSplitterFetch extends Thread { n*7^lAa2  
O{l4 f:51  
zTa5 N  
String sURL; //File URL x:FZEyalG  
long nStartPos; //File Snippet Start Position /"Vd( K2Z  
long nEndPos; //File Snippet End Position XjN4EDi+E  
int nThreadID; //Thread's ID B"_O!  
boolean bDownOver = false; //Downing is over 2GptK"MrD  
boolean bStop = false; //Stop identical v?VDASR2`  
FileAccessI fileAccessI = null; //File Access interface >Q/;0>V  
V$ H(a`!  
h <4`|Bg+  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /i,n75/y?  
{ Lu}jk W*  
this.sURL = sURL; "QnYT3[l"  
this.nStartPos = nStart; c~vhkRA  
this.nEndPos = nEnd; \n[kzi7  
nThreadID = id; VCWW(Y1Fd  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I<#X#_YP  
} $+Ze"E  
G3DgB!  
ov_l)vt  
public void run() +aOdaNcI  
{ I}_}VSG(  
while(nStartPos < nEndPos && !bStop) BY~Tc5  
{ {mJ' Lb0;  
r:bJU1P1$s  
2=_$&oT**  
try{ EHC7b^|3}  
URL url = new URL(sURL); ~X3g_<b_8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F}}!e.>c  
httpConnection.setRequestProperty("User-Agent","NetFox"); #yH+ENp0   
String sProperty = "bytes="+nStartPos+"-"; 2Xe1qzvo  
httpConnection.setRequestProperty("RANGE",sProperty); BH0m[9nU;  
Utility.log(sProperty); 76tn`4NIP  
eUy*0  
&[[r|  
InputStream input = httpConnection.getInputStream(); Nm"P8/-09  
//logResponseHead(httpConnection); NBPP?\1  
!i"zM}  
$9`#p/V  
byte[] b = new byte[1024]; c& ;@i$X(  
int nRead; ..JRtuM-v  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U823q-x  
{ M8~3 0L  
nStartPos += fileAccessI.write(b,0,nRead); #s{^fUN6  
//if(nThreadID == 1) '{ _ X1  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \\R}3 >Wc  
} E]' f&0s  
(u&x.J  
Or? )Nlg6x  
Utility.log("Thread " + nThreadID + " is over!"); I!L J&>  
bDownOver = true; "J"=<_?  
//nPos = fileAccessI.write (b,0,nRead); (m R)o&Y%,  
} -$:; en?  
catch(Exception e){e.printStackTrace ();} (,h2qP-;ud  
} w1tM !4r  
} zP44 Xhz  
e{E\YEc  
:(A&8<}-6  
//打印回应的头信息 &G"s !:  
public void logResponseHead(HttpURLConnection con) /0/ouA>+  
{ PZ|I3z  
for(int i=1;;i++) =Ydrct  
{ >=0]7k;  
String header=con.getHeaderFieldKey(i); T_D3WHp  
if(header!=null) gxl7j Y  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $E@n;0P  
Utility.log(header+" : "+con.getHeaderField(header)); &x1A {j_  
else c-k3<|H`  
break; P*6m~`"5  
} M 2hZ'  
} un 5r9  
A`uHZCwJ5  
iE''>Z  
public void splitterStop() T_S3_-|{==  
{ v*!N}1+J  
bStop = true; K) }1;  
} WAxNQfEe  
(vG*)a  
46g0 e  
} 'JOCL0FP  
gO8d2?Oh  
-yf8  
/* _ dAyw  
**FileAccess.java $BdwKk !k  
*//文件访问(定位,写) uA#K59E+  
package NetFox; _z#" BN  
import java.io.*; ~3.*b% ,  
q KD  
4G,FJjE`p  
public class FileAccessI implements Serializable{  2 q4p-  
9K@ I  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &\ 9%;k  
RandomAccessFile oSavedFile; f- XUto  
long nPos; &<;T$Y  
vqN/crJ@  
DP @1to@  
public FileAccessI() throws IOException /Z6lnm7wJ  
{ B/;> v  
this("",0); *V kaFQZ$,  
} M*0^<e~]F  
q? ">  
bh@CtnO  
public FileAccessI(String sName,long nPos) throws IOException &{? M} 2I  
{ +g g_C'"  
oSavedFile = new RandomAccessFile(sName,"rw"); !CU-5bpu  
this.nPos = nPos; %4LoEm=U  
oSavedFile.seek(nPos); KyNu8s k  
} K[icVT2v~  
+ Tp% *  
)Dz]Pv]H'  
public synchronized int write(byte[] b,int nStart,int nLen) ym|7i9  
{ L ?/AKg  
int n = -1; S=,czs3N  
try{ l6bY!I>  
oSavedFile.write(b,nStart,nLen); EsKgS\`RZ  
n = nLen; hV(^Y)f  
} Z;G*wM"  
catch(IOException e) F- -g?Q^  
{ D>y5&`  
e.printStackTrace (); &)OI!^ (  
} Zye04&x9k  
"Ol:ni1  
zwV!6xG  
return n; \ UrD%;sq  
} 08xo_Oysq  
?XY'<]o E  
KdkL_GSLT  
} U3N d\b'0  
7<)H?;~;  
y7>3hfn~w  
/* S'!&,Dxq^  
**SiteInfoBean.java \(pwHNSafk  
*/ > '=QBW  
package NetFox; ];k!*lR)  
)zxb]Pg+  
L(yUS)O  
public class SiteInfoBean { 2VY7?1Ab(@  
:4zu.  
le \f:  
private String sSiteURL; //Site's URL /''=V.-N  
private String sFilePath; //Saved File's Path f!kZyD7  
private String sFileName; //Saved File's Name )l`Ks  
private int nSplitter; //Count of Splited Downloading File +A?P4}  
Bug.>ln1  
q7lC}'2fu  
public SiteInfoBean() _G'ki.[S7  
{//nSplitter的缺省值为5 82@^vX  
//default value of nSplitter is 5 ?7Cm+J  
this("","","",5); >>T7;[h  
} p(pfJ^/:(  
PV#h_X<l%  
B6dU6"  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !-`L1D_hy  
{ %w^*7Oi  
sSiteURL= sURL; A{s -g>s  
sFilePath = sPath; zH~P-MqC  
sFileName = sName; MJiVFfYW  
this.nSplitter = nSpiltter; ntH`\ )xi  
F2 B(PGa7  
h |]cZMGo  
} +\Vw:~e  
~+1mH  
KfjWZ4{v  
public String getSSiteURL() _+48(Q F<  
{ ;J|t-$Z  
return sSiteURL; Az@@+?,%Y  
} X[$h &]  
he~8V.$  
$\ZWQct  
public void setSSiteURL(String value) fJ8>nOh  
{ Q`*U U82!  
sSiteURL = value; <5G(Y#s/?  
} )f$4: Pq  
`F/R:!v  
E "=4(   
public String getSFilePath()  +#,J`fV%  
{ Z5TA4Q+Q  
return sFilePath; Rf0so   
} we _CF*zj  
]AA|BeL?|  
d2eXN3"  
public void setSFilePath(String value) XB!qPh .  
{ L'Cd` .yVO  
sFilePath = value; A4,%l\di<  
} BlpyE[h T  
JE}VRMNr  
5, ,'hAq_  
public String getSFileName() !@lx|= #  
{ a!bW^?PcK  
return sFileName; U Y*`R  
} L91vp'+2  
f#&z m} t  
}6^5mhsL  
public void setSFileName(String value) L E\rc A  
{ Tl yyJ{~  
sFileName = value; ?<jWEz=  
} [q%`q`EG  
60|PVsmDm  
.<?7c!ho  
public int getNSplitter() ;@S'8  
{ |9XoRGgXU  
return nSplitter; v_Vw!u  
} e'uC:O.u  
)w4U]inJ$"  
MUbKlX  
public void setNSplitter(int nCount) zlP{1z;nV  
{ _LZ(HTX~  
nSplitter = nCount; gd * b0(  
} lZRO"[<  
} 3U^Vz9LW  
j~Pw t9G  
[<,7LG<  
/* v76P?[  
**Utility.java gw"SKp!]  
*/ w-JWMgY8w  
package NetFox; [5' HlHK  
Ba?1q%eG  
! $mY.uu  
public class Utility { +w[ZMk  
#C } +  
I )yaR+l  
public Utility() } O+xs3Uv  
{ iPl,KjGk  
<xSh13<  
&-FG}|*4M  
} :ILpf+`yY  
%Qz<Lk">.  
//线程睡眠 MOh&1]2j5  
public static void sleep(int nSecond) Pqx?0 f)  
{ 3r#['UmT  
try{ W*s=No3C  
Thread.sleep(nSecond); P !f{U;B  
} \mLEwNhRY  
catch(Exception e) `W}pA mhj  
{ ? ch?q~e)  
e.printStackTrace (); oU,8?( }'~  
} 9O&m7]3  
} z*.G0DFw  
423%K$710  
//日志 cvy 5|;-u  
public static void log(String sMsg) ]#4kqj}  
{ q !9;JrX  
System.err.println(sMsg); 00D.Jn  
} ;bG?R0a  
jMBM qQNU  
j5R0e}/r  
public static void log(int sMsg) p,k1*|j  
{ h1 (i/{}:  
System.err.println(sMsg); 1o/(fy  
} OcMB)1uh\  
} >"1EN5W  
T^] ]z}k  
Q?T+^J   
/* (KN",u6F  
**TestMethod.java jNx{*2._r  
*/ $k )K}U  
package NetFox; kF'9@*?J  
qbSI98r w  
g$C]ln>"9m  
public class TestMethod { 3pML+Y|ij  
p=UW ^95  
N`7OJ)l  
public TestMethod() e;~(7/1  
{ ///xx/weblogic60b2_win.exe c.1gQy$}|  
try{ JE{ cZ<NNH  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2hNl_P~z1u  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +JG05h%'  
SiteFileFetch fileFetch = new SiteFileFetch(bean); k@%5P-e}  
fileFetch.start(); >{(c\oMD  
} k(tB+k!vH\  
catch(Exception e){e.printStackTrace ();} !21G $ [H  
UVLS?1ra  
CLZ j=J2  
} >0:3CpO*  
O[$X36z  
n~ $S  
public static void main(String[] args) aC=2v7*  
{ 0sSBwG  
new TestMethod(); NUb$PT  
} bA 0H  
} ORKJy )*"  
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