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http断点续传简单实现(java)

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/* 59$mfW o>  
**SiteFileFetch.java 4eU};Pv  
*/ WWrD r  
package NetFox; ro}plK(<WQ  
import java.io.*; 'iXjt MX  
import java.net.*; $$A{|4,aI  
hs2f3;)  
|B)e! #  
public class SiteFileFetch extends Thread { W2%(a0p  
&%f y  
>>(2ZJ  
SiteInfoBean siteInfoBean = null; //文件信息Bean Z!G;q}zZ!  
long[] nStartPos; //开始位置 NX@TWBn%  
long[] nEndPos; //结束位置 A}~hc&J  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 T_[W=9  
long nFileLength; //文件长度 }&y>g0$@  
boolean bFirst = true; //是否第一次取文件 O(~`fN?n  
boolean bStop = false; //停止标志 ?j ?{} Z  
File tmpFile; //文件下载的临时信息 UG Fx  
DataOutputStream output; //输出到文件的输出流 f3y_&I+zl  
m1]rLeeEt  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) q_OIzZ@  
public SiteFileFetch(SiteInfoBean bean) throws IOException J0d +q!  
{ ?lR)Hi  
siteInfoBean = bean; +z>*m`}F  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); =H>rX 2k  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 0w8Id . ,  
if(tmpFile.exists ()) WB6g i2  
{ 7Q 0 M3m  
bFirst = false; }!Qo wG   
read_nPos(); 6xk"bIp  
} /A_</GYs  
else  YDi_Gl$  
{ @r+ErFI  
nStartPos = new long[bean.getNSplitter()]; 1 YMaUyL 1  
nEndPos = new long[bean.getNSplitter()];  R(k6S  
} z+PSx'#}  
Yah3I@xGy  
y<BiR@%,7  
p|(910OEQ  
} `r_qvrC  
T"kaOy  
!ye%A&  
public void run() ^yy\CtG  
{ o$d; Y2K  
//获得文件长度 %lv2;-  
//分割文件 M`BD]{tN}  
//实例FileSplitterFetch YwoytoXK  
//启动FileSplitterFetch线程 Fdm7k){A  
//等待子线程返回 1_7x'5GdA  
try{ %CF(SK2w  
if(bFirst) # Sb1oLC  
{ 4%\L8:  
nFileLength = getFileSize(); .A\9|sRZ5  
if(nFileLength == -1) ETSBd[  
{ &:akom8  
System.err.println("File Length is not known!"); wXuHD<<  
} _m3PAD4  
else if(nFileLength == -2) s,K @t_J  
{ +wD--24!(  
System.err.println("File is not access!"); DI!NP;E  
} Yi7`iC  
else b'M g  
{ &1]}^/u2  
for(int i=0;i<nStartPos.length;i++) e`k 2g ^  
{ Fd5{pM3  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); +Y)rv6}m  
} "4`h -Y  
for(int i=0;i<nEndPos.length-1;i++) {n$9o  
{ egx(N <  
nEndPos = nStartPos[i+1]; e_k1pox]l  
} fcnbPO0M  
nEndPos[nEndPos.length-1] = nFileLength; +c}fDrr)  
} ;OPzT9  
} {-Yp~HQF  
GG(rp]rgl  
HxU.kcf  
//启动子线程 q6H90Zb  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !rTh+F*  
for(int i=0;i<nStartPos.length;i++) aWOApXJ  
{ JaG<.ki  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~`T(mh',  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZzzQXfA#  
nStartPos,nEndPos,i); iknBc-TLD  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9Hlu%R  
fileSplitterFetch.start(); hd/5*C{s  
} qIA!m .GC  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,8+SQo #3  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p8Lb*7W  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ",  PovPO  
nEndPos = " + nFileLength); _)2N Fq  
// fileSplitterFetch[nPos.length-1].start(); cU%#oEMf<  
uZm<:d2%)  
`5[VO  
//等待子线程结束  <gf:QX!  
//int count = 0; ?v8RY,Q30  
//是否结束while循环 \&@Tq-o  
boolean breakWhile = false; #^!oP$>1  
dlJkxEh 2  
cg1<  
while(!bStop) <wj2:Z0  
{ r{>tTJFD(:  
write_nPos(); {< jLfL1  
Utility.sleep(500); %J~8a_vO  
breakWhile = true; ]~3wq[O  
I0m/   
/A|ofAr)  
for(int i=0;i<nStartPos.length;i++) KM< M^l_Q  
{ si3i#l&.b_  
if(!fileSplitterFetch.bDownOver) )bi*y`UM]  
{ @hl5^d"l  
breakWhile = false; VI" ,E}  
break;  Gp@Y=mU  
} 8 l}tYl`|  
} | 2p\M?@  
if(breakWhile) 8{%/!ylJz  
break; L!mQP  
;X|;/@@  
zr84%_^  
//count++; *v l_3S5_  
//if(count>4) HmbTV(lC  
// siteStop(); G dL\  
} 8N ci1o  
=*"Amd,  
uW Q`  
System.err.println("文件下载结束!"); ik7#Og~ 3  
} gqZ7Pro.  
catch(Exception e){e.printStackTrace ();} uZd)o AB  
} MT%ky  
hLx*$Z>  
3w!oJB  
//获得文件长度 wpx,~`&  
public long getFileSize() \&ERSk2  
{ GlQ=M ) E  
int nFileLength = -1; aH'^`]'_=  
try{ |06J4H~k  
URL url = new URL(siteInfoBean.getSSiteURL()); 7dV^35 KP  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0S/&^  
httpConnection.setRequestProperty("User-Agent","NetFox"); \ E[0KvN;O  
PCt&66F   
8Q#&=]W$  
int responseCode=httpConnection.getResponseCode(); sDJ5'ul  
if(responseCode>=400) Br \/7F  
{ gJ vc<]W8!  
processErrorCode(responseCode); 2kCJqyWy  
return -2; //-2 represent access is error 6K?+adKlc  
} ^4 es  
5>h2WL  
pA+Qb.z5z  
String sHeader; -lb}}z+/  
/*r MveT  
oDKgW?x  
for(int i=1;;i++) Pbm ;@ V  
{ Wd~}O<"  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9FPl  
//Utility.log(in.readLine()); s_D7?o  
sHeader=httpConnection.getHeaderFieldKey(i); K8284A8v  
if(sHeader!=null) FY#`]124*  
{ 1D=My1B  
if(sHeader.equals("Content-Length")) GbB&kE3KP  
{ Haq23K  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); eUF PzioW  
break; 1REq.%/=  
} Gp32\^H|<  
} 2z )h,<D  
else _@?]!J[  
break; w:z_EV!&  
} r'xa' 6&  
} -J? df  
catch(IOException e){e.printStackTrace ();} f4@Dn >BJ  
catch(Exception e){e.printStackTrace ();} z81I2?v[Jr  
BtU,1`El5  
El"XF?OgpP  
Utility.log(nFileLength); tC|5;'m.2  
Fo~C,@/Qt  
2<u vz<B  
return nFileLength; Z(xn-  
} V :d/;~  
hDmVv;M:  
*2;w;(-s  
//保存下载信息(文件指针位置) ]S;e#u{QE  
private void write_nPos() f)"O( c  
{ x6:$lZ(  
try{ ~POe0!}  
output = new DataOutputStream(new FileOutputStream(tmpFile)); %pTbJaM\U  
output.writeInt(nStartPos.length); 0FEb[+N  
for(int i=0;i<nStartPos.length;i++) QbOm JQ  
{ ;YK^&!N  
// output.writeLong(nPos); ;=B&t@  
output.writeLong(fileSplitterFetch.nStartPos); IXd&$h]Lq  
output.writeLong(fileSplitterFetch.nEndPos); ~jF5%Gu  
} |$bZO`^  
output.close(); 7J$ ^R6rh  
} 3@6f%Dyj  
catch(IOException e){e.printStackTrace ();} Oe2Tmvl  
catch(Exception e){e.printStackTrace ();} &w/aQs~  
} U$0#j  
r}*2~;:pW  
9H.E15B  
//读取保存的下载信息(文件指针位置) <C CEqY 4  
private void read_nPos() 0{AVH/S  
{ :hxfd b-  
try{ 9J2% 9,^  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); FUq@ dUv  
int nCount = input.readInt(); BT`/O D@  
nStartPos = new long[nCount]; < >f12pu  
nEndPos = new long[nCount]; hr]NW>;  
for(int i=0;i<nStartPos.length;i++) /\#qz.c2K  
{ N;Hf7K  
nStartPos = input.readLong(); %v}:#_va]  
nEndPos = input.readLong(); .HGEddcC  
} hQ<"  
input.close(); XPWK"t0 1  
} mYa0_P%^  
catch(IOException e){e.printStackTrace ();} ~^Vt)/}Q  
catch(Exception e){e.printStackTrace ();} HnOp*FP  
} ''f  
A:NsDEt  
7cvbYP\<lv  
private void processErrorCode(int nErrorCode) hnE@+(d=qJ  
{  $7|0{Dw  
System.err.println("Error Code : " + nErrorCode); B;G|2um:$  
} {#Gr=iv~N  
`[o^w(l:5@  
tYmWze. j  
//停止文件下载 ,`-6!|:  
public void siteStop() )G*H l^Z;4  
{ wPqIy}-  
bStop = true; Qj 0@^LA  
for(int i=0;i<nStartPos.length;i++) ZH&%D*a&  
fileSplitterFetch.splitterStop(); |? r,W ~9`  
c#CX~  
; [dcbyu@  
} >@T ZYdl  
} !>t |vgW  
//负责部分文件的抓取 rJ!xzge;G  
**FileSplitterFetch.java =A=er1~%  
*/ c*1B*_08  
package NetFox; 3(FJ<,"D}  
'lIT7MK  
:/Sx\Nz78  
import java.io.*; M[TgNWl/[  
import java.net.*; eJJvEvZ,  
7i 6-Hq  
UyK|KL  
public class FileSplitterFetch extends Thread { R<k4LHDy  
Fz>J7(Y.j  
dc%+f  
String sURL; //File URL Is?0q@  
long nStartPos; //File Snippet Start Position T4\,b  
long nEndPos; //File Snippet End Position trgj]|?M  
int nThreadID; //Thread's ID Z8nNZ<k  
boolean bDownOver = false; //Downing is over LD^V="d  
boolean bStop = false; //Stop identical % YU(,83(+  
FileAccessI fileAccessI = null; //File Access interface 4y)"IOd#|  
oD!72W_:  
N,Y<mX  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3G5i+9Nt.L  
{ Ij{{Z;o3  
this.sURL = sURL; ? )0U!)tK  
this.nStartPos = nStart; *,pG4kh!  
this.nEndPos = nEnd; 0XXu_f@]9  
nThreadID = id; tlvLbP*r  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r6MQ|@  
} r 97 VX>  
O]lWaiR`  
~}wPiu,  
public void run() P9Rq'u  
{ T7!a@  
while(nStartPos < nEndPos && !bStop) |\N[EM%.@  
{ .c~;/@{  
5O*. qp?  
c%i/ '<Afr  
try{ 2r[Q$GPM<  
URL url = new URL(sURL); fqvA0"tv  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SDdK5@1O4o  
httpConnection.setRequestProperty("User-Agent","NetFox"); bl}$x/  
String sProperty = "bytes="+nStartPos+"-"; f]o DZO%^  
httpConnection.setRequestProperty("RANGE",sProperty); 9e8@0?0  
Utility.log(sProperty); oa;[[2c  
=_L"x~0I-  
1Qf5H!5vx  
InputStream input = httpConnection.getInputStream(); Mgf80r=  
//logResponseHead(httpConnection); t{84ioJ"$  
hDVD@b  
~v+& ?dg  
byte[] b = new byte[1024]; b6);bX>e  
int nRead; pm<<!`w"  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }$m_):t@@  
{ u4+)lvt  
nStartPos += fileAccessI.write(b,0,nRead); c67O/ B(  
//if(nThreadID == 1) Ak>RLD25_  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =X-$k k  
} 0~n= |3*P  
^HC! my  
iFga==rw  
Utility.log("Thread " + nThreadID + " is over!"); jC; XY!d6  
bDownOver = true; ^$rt|]  
//nPos = fileAccessI.write (b,0,nRead); 1N:eM/a  
} d![EnkyL;  
catch(Exception e){e.printStackTrace ();} @@!t$dD  
} 7jEAhi!Cq(  
} Z@~8iAgE  
W&Fa8  
PjRKYa_U  
//打印回应的头信息 3tOnALv  
public void logResponseHead(HttpURLConnection con) QE-t v00  
{ l2n>Wce9  
for(int i=1;;i++) I>ofSaN  
{ 0]i#1Si~@  
String header=con.getHeaderFieldKey(i); a)`h*P5@  
if(header!=null) .Jou09+  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \N/T^,  
Utility.log(header+" : "+con.getHeaderField(header)); PT>,:zY  
else #pOW2 Uj8\  
break; EeL~`$f  
} ` LU&]NS3  
} kiqq_`66  
'4N[bRCn  
 (lt/ t  
public void splitterStop()  !X |Tf  
{ %T1(3T{Li  
bStop = true; ]+fL6"OD/2  
} ){8^l0b  
~#) DJ  
?t?!)#X  
} ]9b*!n<z  
H( cY=d,  
#?8'Z/1 )  
/* [.3M>,)+-  
**FileAccess.java .,tf[w 71  
*//文件访问(定位,写) :5C9uW #  
package NetFox; GT#iY*  
import java.io.*; MF%9  
K$f~Fft  
ob-be2EysH  
public class FileAccessI implements Serializable{ `?`\!uP"  
?vM{9!M  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Hyc19|  
RandomAccessFile oSavedFile; +O\6p  
long nPos; 1gCp/m2r7  
' 71D:%p  
qItj`F)d  
public FileAccessI() throws IOException kj+AsQC ,  
{ umD .  
this("",0); `[Z?&'CRQ  
} oh,Nu_!  
IsnC_"f  
S@T> u,t'  
public FileAccessI(String sName,long nPos) throws IOException +gK7`:v4O*  
{ dHd{9ftyF  
oSavedFile = new RandomAccessFile(sName,"rw"); B#sc!eLmU&  
this.nPos = nPos; qmJFXnf  
oSavedFile.seek(nPos); %o*afd  
} X8?|5$Ey  
4sROMk=l  
[+ 1([#  
public synchronized int write(byte[] b,int nStart,int nLen) )mp0k%  
{ VYlg+MlT0  
int n = -1; &5C%5C~ch  
try{ h:j-Xd$H+  
oSavedFile.write(b,nStart,nLen); nD E5A  
n = nLen; T>W(Caelq  
} tAYu|\]  
catch(IOException e) ^VoQGP/cl  
{ Ml0d^l}'  
e.printStackTrace (); BKVvu}V(o  
} wk)gxn1A,  
@Q TG  
Z#^2F8,]  
return n; &W|'rA'r  
}  21w<8:Vg  
I"Y?vj9]  
A}[Lk#|n  
} /T*{Mo{B  
vC+mC4~/(  
Q7`zrCh  
/* o$Hc5W([Z  
**SiteInfoBean.java DHm$gk  
*/ v)rN] b]  
package NetFox; +h*&r ~T  
S.M< (  
jZ.+b j >  
public class SiteInfoBean { + ZGOv,l  
NE3G!qxL  
+.[#C5  
private String sSiteURL; //Site's URL >8jDW "Ua  
private String sFilePath; //Saved File's Path 5M*q{kX)  
private String sFileName; //Saved File's Name ZhM-F0;`  
private int nSplitter; //Count of Splited Downloading File o<T>G{XYB  
dI'C[.zp[  
e`8z1r  
public SiteInfoBean() gY;N>Yq,C  
{//nSplitter的缺省值为5 vjbot^W9  
//default value of nSplitter is 5 6 U# C  
this("","","",5); ;?%2dv2d  
} Q;5aM%a`  
&[JI L=m5  
b @5&<V;r2  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vJXd{iQE@C  
{ H+_oK ]/  
sSiteURL= sURL; x"U/M ?l  
sFilePath = sPath; QT^( oog=  
sFileName = sName; I]ywO4  
this.nSplitter = nSpiltter; zXZy:SD  
:sM|~gT  
 <}B|4($  
} +Y 3_)  
0-FwHDxw  
xAz gQ  
public String getSSiteURL() ^W#[6]S  
{ @yobT,DXi  
return sSiteURL; XTHrf'BU  
} 'KyT]OObS  
K\n %&w  
$m{\<A  
public void setSSiteURL(String value) Wpj.G  
{ nc@ul')  
sSiteURL = value; x-Xb4?{  
} 6^|bKoN/ f  
`qs'={YtU  
C|z`hNp  
public String getSFilePath() ~oSLWA9  
{ cDE?Xo'!  
return sFilePath; '!IX;OSjH  
} Fd|:7NRA<  
<*4=sX@  
{jlm]<:&Z  
public void setSFilePath(String value) ?;uzx7@F  
{ .[K{;^>  
sFilePath = value; 9HP)@66  
} Oi l>bv8  
l  4~'CLi  
MY1 tYO  
public String getSFileName() RAf+%h*  
{ &QCqaJ-  
return sFileName; V 9=y@`;  
} w&f29#i;b  
unjo&  
f ( UcJx  
public void setSFileName(String value) Fi*6ud\n!  
{ r@s, cCK9?  
sFileName = value; ]l+2Ca:-[j  
} ub.pJJlC  
:!{aey  
uiHlaMf  
public int getNSplitter() `EWeJ(4Z@  
{ )Tb{O  
return nSplitter; 4p %`Lv  
} :(I)+;M}P  
@JN%P} 4)  
)t)tk=R9N  
public void setNSplitter(int nCount) dqd Qt_  
{ B%'Np7  
nSplitter = nCount; ,9W0fm \t  
} vi lNl|  
} ,wZ[Y 3  
xB9^DURr\  
7g(rJGjtg  
/* Hi.JL  
**Utility.java >@]E1Qfe  
*/ ;'p0"\SV  
package NetFox; 73N%_8DH  
a.w,@!7  
1d-j_ H`s  
public class Utility { %NxNZe  
<NS= <'U  
xbn+9b  
public Utility() 4b7}Sr=`  
{ S0p]:r ";x  
E 8,53$  
EHo"y.ODg  
} Qj3UO]>  
17};I7  
//线程睡眠 G_dia6  
public static void sleep(int nSecond) *OsXjL`f  
{ O#u)~C?)8  
try{ ~ RTjcE  
Thread.sleep(nSecond); @h ^5*M  
} gdkO|x  
catch(Exception e)  hA/FK  
{ 5!y3=.j  
e.printStackTrace (); W>1\f0'  
} rEddX  
} S93NsrBbY  
C"0gAN  
//日志 bS0^AVA  
public static void log(String sMsg) Zsf<)Vx  
{ guFR5>-L  
System.err.println(sMsg); Fb-NG.Z#  
} LM*9b  
CR, Y%0vQ  
a?+) K  
public static void log(int sMsg) Z39^nGO  
{ >1joCG~  
System.err.println(sMsg); ?]paAP;4  
} 1X#`NUJ?2  
} w8@MUz}/#  
xES+m/?KlZ  
6EPC$*Xp!  
/*  JTz1M~  
**TestMethod.java @&h<jM{D  
*/ 0*tEuJ7  
package NetFox; * z{D}L-&  
gb@!Co3  
<u^41  
public class TestMethod { ! '2'db  
u# %7>=  
&s] s]V)  
public TestMethod() egP3q5~  
{ ///xx/weblogic60b2_win.exe k W-5H;>  
try{ #!, xjd  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,pAMQ5  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [ >vS+G  
SiteFileFetch fileFetch = new SiteFileFetch(bean); y& Dd  
fileFetch.start(); 8mCr6$|%  
} %*jpQOw  
catch(Exception e){e.printStackTrace ();} XWB>' UDQ#  
tQ|b?3  
]JhtO{  
} a"WnBdFZ  
~vF.k,  
n,AN&BZ  
public static void main(String[] args) ^//N-?Fx  
{ u2Rmp4]  
new TestMethod(); (:[><-h.  
} zIdQ^vm8Q  
} *>\RGL;]8  
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