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http断点续传简单实现(java)

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/* ?w6zq|  
**SiteFileFetch.java par| j]  
*/ c@9jc^CJ  
package NetFox; "^E/N},%u5  
import java.io.*; PhBdm'  
import java.net.*; }% (e`[?1  
7 j$ |fS  
E +\?|q !T  
public class SiteFileFetch extends Thread { > w:+nG/r  
lg` Qi&  
>;V ? s]  
SiteInfoBean siteInfoBean = null; //文件信息Bean #U45H.Rz  
long[] nStartPos; //开始位置 y,&.<Yc  
long[] nEndPos; //结束位置 b<,Z^Z_  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ]"bkB+I  
long nFileLength; //文件长度 jO xH' 1I  
boolean bFirst = true; //是否第一次取文件 `L p3snS  
boolean bStop = false; //停止标志 XQL"D)fw  
File tmpFile; //文件下载的临时信息 #?%akQ+w  
DataOutputStream output; //输出到文件的输出流 Sh'>5z2  
rmpx8C Y"  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) k8fvg4  
public SiteFileFetch(SiteInfoBean bean) throws IOException lU]/nKyd  
{ %gj's-!!  
siteInfoBean = bean; '@enl]J  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); BDoL)}bRE  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); +~, qb1aZ  
if(tmpFile.exists ()) 6J. [9#  
{ AQkH3p/W  
bFirst = false; SN2X{Q|*  
read_nPos(); S~jl%]  
} ga0>J_  
else iC-WQkQY  
{ N<c98  
nStartPos = new long[bean.getNSplitter()];  E~oQ%X~  
nEndPos = new long[bean.getNSplitter()]; = 7U^pT  
} w?_y;&sbR  
MQ;c'?!5[!  
 +C3IP  
VB6EM|bphl  
} wI'8B{[  
yNp l0 d  
Cb}hE ro  
public void run() ,VZ;=  
{ dm3cQ<0  
//获得文件长度 ^]mwL)I}  
//分割文件 tln*Baq  
//实例FileSplitterFetch T' O5> e  
//启动FileSplitterFetch线程 OiPE,sv  
//等待子线程返回 RqTW$94RD  
try{ jU')8m[  
if(bFirst) Dw}8ci'  
{ ,arFR'u>  
nFileLength = getFileSize(); gM=oH   
if(nFileLength == -1) M7Ej#Y  
{ Oi{X \Y  
System.err.println("File Length is not known!"); y Q\K;  
} U9:?d>7  
else if(nFileLength == -2) ,EPs>#d  
{ zt/p' khP3  
System.err.println("File is not access!"); gb 6 gIFq;  
} y[7*^9J  
else 7{=<_  
{ m~s.al(G91  
for(int i=0;i<nStartPos.length;i++) &.k'Dj2hf  
{ |~mq+:44+  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); (WT0 j  
} }W&hPC  
for(int i=0;i<nEndPos.length-1;i++) S.o 9AUv9  
{ )@DT^#zR  
nEndPos = nStartPos[i+1]; aYQ!`mS::M  
} v5"5UPi-  
nEndPos[nEndPos.length-1] = nFileLength; g Z3VT{  
} [\N,ow,n  
} oQJK}9QR  
9vc3&r  
arf`%9M  
//启动子线程 :nki6Rkowt  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <p<jXwl  
for(int i=0;i<nStartPos.length;i++) xR5jy|2JJ  
{ *yAC8\v  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rg U$&O  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /'U/rjb_h{  
nStartPos,nEndPos,i); KA:>7-  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >@^z?nb  
fileSplitterFetch.start(); c_b^t09  
} ?8wFT!J  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]/;0  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <qH>[ \  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CL/8p;  
nEndPos = " + nFileLength); K~$o2a e  
// fileSplitterFetch[nPos.length-1].start(); )fSQTbB;0  
-L7Q,"a$  
(bH*i\W  
//等待子线程结束 [sG=(~BU  
//int count = 0; U(5(0r  
//是否结束while循环 w?kdM1T  
boolean breakWhile = false; Zcd!y9]#  
k>#,1GbNZy  
,lm.~%}P*  
while(!bStop) e#`wshtN:  
{ 4)Y=)#=  
write_nPos(); W2h^ShG  
Utility.sleep(500); P\bW kp0  
breakWhile = true; <~# ZtD$G  
`+]9+:tS  
)_!t9gn*wr  
for(int i=0;i<nStartPos.length;i++) fx|$(D@9  
{ JBQ,rX_Hw  
if(!fileSplitterFetch.bDownOver) R{S{N2+p(  
{ M@@"-dy  
breakWhile = false; UNLy{0tA  
break; 2GECcx53  
} . (*V|&n  
} K V ^ `  
if(breakWhile) hnS ~r4  
break; vW6Pf^yJ  
Vf6lu)Z c1  
ehj&A+Ip  
//count++; "PGEiLY  
//if(count>4) ]5D?Sc#-  
// siteStop(); DV +DJcF  
} #9z\Wblr  
u#XNl":x  
V ea>T^  
System.err.println("文件下载结束!"); A"`6 2  
} h$|K vS  
catch(Exception e){e.printStackTrace ();} xin<.)!E  
} WQ4:='(  
4A0R07"  
Z[KXDQn8  
//获得文件长度 B&|F9Z6D  
public long getFileSize() y|V/xm+Fp  
{ )ARfI)<1b  
int nFileLength = -1; l i}4d+  
try{ 7QL>f5Q  
URL url = new URL(siteInfoBean.getSSiteURL()); <jU[&~p  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ch,<4E/c[R  
httpConnection.setRequestProperty("User-Agent","NetFox"); c:"*MM RC  
k!O#6Z  
7~TE=t  
int responseCode=httpConnection.getResponseCode(); t6_6Bl:  
if(responseCode>=400) ?1}1uJMj-  
{ j['Z|Am"l  
processErrorCode(responseCode); LKY4rY!|@d  
return -2; //-2 represent access is error &!J X  
} {6'5K U*RH  
Y cE:KRy  
X4*{CM  
String sHeader; mzTF2K  
> taT;[Oa  
Z 2Fm=88  
for(int i=1;;i++) 4%2QF F @  
{ (.7_`T6QG  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <9eQ  
//Utility.log(in.readLine()); ("o <D{A  
sHeader=httpConnection.getHeaderFieldKey(i); 2S}%r4$n}  
if(sHeader!=null) qQ%zSJ?  
{ ORlz1 &hW  
if(sHeader.equals("Content-Length")) HH+NNSRO  
{ |{cdXbr  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /ow/)\/}  
break; 2qKo|'gL`  
} sl-LX)*N#  
} T=: &W3  
else ^sd+s ~ xx  
break; MzYTEe&-L  
} K$(&Qx}  
} Z'<=06  
catch(IOException e){e.printStackTrace ();} ^*'|(Cv  
catch(Exception e){e.printStackTrace ();} j#y_#  
z^I"{eT8  
~|@aV:k  
Utility.log(nFileLength); gt6*x=RCrQ  
|ap{+ xh  
)ruC_)  
return nFileLength; r|cl6s!P  
} EaFd1  
pm B}a7  
ja70w:ja  
//保存下载信息(文件指针位置) c`mJrS:  
private void write_nPos() b_cnVlN[  
{ Y'Sxehx  
try{ ?mS798=f  
output = new DataOutputStream(new FileOutputStream(tmpFile)); C*ZgjFvB  
output.writeInt(nStartPos.length); Xj"/6|X  
for(int i=0;i<nStartPos.length;i++) fG;)wQJ  
{ `R0>;TdT  
// output.writeLong(nPos); L7_Mg{  
output.writeLong(fileSplitterFetch.nStartPos); U2/H,D  
output.writeLong(fileSplitterFetch.nEndPos); 5.F.mUO  
} @no]*?Gpa  
output.close(); akgXI^K  
} (qlI QC  
catch(IOException e){e.printStackTrace ();} Q[scmP^$^  
catch(Exception e){e.printStackTrace ();} p=\DZU~1  
} 4?g~GI3  
z|F>+6l"Y7  
4z Af|Je  
//读取保存的下载信息(文件指针位置) EonZvT-D=  
private void read_nPos() :Y(Yk5  
{ NWNH)O@  
try{ +cM;d4  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p 9XHYf72  
int nCount = input.readInt(); (\.[pj%-O  
nStartPos = new long[nCount]; lZV]Z3=p'0  
nEndPos = new long[nCount]; e<YC=67n)  
for(int i=0;i<nStartPos.length;i++) +|r;t  
{ lYv :  
nStartPos = input.readLong(); fo&q/;l\  
nEndPos = input.readLong(); !0c7nzjm  
} .\X/o!xC  
input.close(); zA9N<0[]o  
} 6(B0gBCId  
catch(IOException e){e.printStackTrace ();} [=u8$5/a  
catch(Exception e){e.printStackTrace ();} Q#urx^aw  
} `r'q(M  
XJ?|\=]  
"v/^nH  
private void processErrorCode(int nErrorCode) )FT~gl%  
{ 5H:NY|  
System.err.println("Error Code : " + nErrorCode); u9"b,].b  
} ' IFbD["r  
q`E6hm  
0aSN 8  
//停止文件下载 (' /S~  
public void siteStop() djqSW9  
{ ii2X7Q  
bStop = true; a2v UZhkR  
for(int i=0;i<nStartPos.length;i++) `hM`bcS  
fileSplitterFetch.splitterStop(); ~^$ONmI5  
Thn-8DT  
^=bJ _'  
} 9~ajEs  
} *'`ByS  
//负责部分文件的抓取 LTS3[=AB  
**FileSplitterFetch.java ] $$ciFM  
*/  UB&ofO  
package NetFox; b.47KJzt  
IpGq_TU  
fC.-* r  
import java.io.*; %Gl,V5z&  
import java.net.*; Y<:%_]]  
44f8Hc1g  
n0 _:!]k^  
public class FileSplitterFetch extends Thread { eT[ ,k[#q  
RZjTUMAz4  
[WXtR  
String sURL; //File URL _D1bR7  
long nStartPos; //File Snippet Start Position ,[,+ _A  
long nEndPos; //File Snippet End Position M ioS  
int nThreadID; //Thread's ID )J<Li!3  
boolean bDownOver = false; //Downing is over "'94E,W  
boolean bStop = false; //Stop identical }h5pM`|1  
FileAccessI fileAccessI = null; //File Access interface .^I,C!O#  
u]@``Zb|  
)K -@{v^|  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /XEcA 5C<  
{ eg~$WB;1  
this.sURL = sURL; (NOAHV0H  
this.nStartPos = nStart; 7n,nODbJ  
this.nEndPos = nEnd; g}{Rk>k  
nThreadID = id; bnUpH3  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 GuQ3$B3j  
} 7XT2d=)"  
BqvOi~ l  
)_ NQ*m  
public void run() FfI $3:9  
{ D *Siy;  
while(nStartPos < nEndPos && !bStop) \! Os!s  
{  DC]FY|ff  
g v&xC 6>  
+z+25qWi  
try{ <\8dh(>  
URL url = new URL(sURL); Yt++  ?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;EW]R9HCH  
httpConnection.setRequestProperty("User-Agent","NetFox"); 93kSBF#  
String sProperty = "bytes="+nStartPos+"-";  h#^IT  
httpConnection.setRequestProperty("RANGE",sProperty); @NlnZfMu  
Utility.log(sProperty); @bmu4!"d  
{[hV ['Awv  
f5 wn`a~h  
InputStream input = httpConnection.getInputStream(); hx+a.N  
//logResponseHead(httpConnection); kMo;<Z  
L'J$jB5cP  
mJc'oG-  
byte[] b = new byte[1024];  P%xk   
int nRead; 1N x%uz  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9j49#wG0"B  
{ _T6WA&;8  
nStartPos += fileAccessI.write(b,0,nRead); [`=|^2n?  
//if(nThreadID == 1) igOjlg_Q  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L=Dd`  
} 5Jp@n .  
28d:  
.oO_x>  
Utility.log("Thread " + nThreadID + " is over!"); =9i:R!,W  
bDownOver = true; x/~V ZO  
//nPos = fileAccessI.write (b,0,nRead); ]Q-ON&/  
} #PVgx9T=_  
catch(Exception e){e.printStackTrace ();} ]r$S{<  
} Axk p  
} "6Nma)8  
"@ Zy+zLU  
}pu2/44=W  
//打印回应的头信息 4Yt:PN2  
public void logResponseHead(HttpURLConnection con)  F04`MY"  
{ j{7_p$JM  
for(int i=1;;i++) 1e'-rm F  
{ }bIEWho  
String header=con.getHeaderFieldKey(i); @0A0\2  
if(header!=null) O1JGv8Nr  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); FGr0W|?v  
Utility.log(header+" : "+con.getHeaderField(header)); fH`P8?](x  
else "#rlL^9v  
break; S!#7]wtbP  
} ?%JH4I2  
} qK:.j  
Um9!<G=;  
#`:60#l  
public void splitterStop() \'GX^0yK  
{ @=K> uyB  
bStop = true; xRv1zHZ  
} {p 9y{$  
I=D`:u\H  
> 9JzYI^  
} _ Eq:Qbw#  
\$VtwVQ,b  
:?RooJ~#  
/* 3.Ni%FF`  
**FileAccess.java qX0IHe  
*//文件访问(定位,写) I:]s/r7  
package NetFox; Vd)iv\a  
import java.io.*; e&8pTD3  
}Da8S|)H  
'iXjt MX  
public class FileAccessI implements Serializable{ .<u<!fL2  
UI<'T3b  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hs2f3;)  
RandomAccessFile oSavedFile; "2'nLQ""q  
long nPos; [uc;M6o}?  
j &,vju  
'#4ya=Ww  
public FileAccessI() throws IOException kR-N9|>i  
{ &hB~Z(zS!  
this("",0); Z!G;q}zZ!  
} GaSk &'n$Y  
+TpM7QaL  
UB.FX  
public FileAccessI(String sName,long nPos) throws IOException h[C!cX  
{ h}q+Dw.i  
oSavedFile = new RandomAccessFile(sName,"rw"); 6b-d#H/1Y  
this.nPos = nPos; Z:,HB]&;9  
oSavedFile.seek(nPos); >P>.j+o/  
} (4$lB{%  
4D$$KSa  
C(}9  
public synchronized int write(byte[] b,int nStart,int nLen) S?OK@UEJ  
{ s]5wzbFO  
int n = -1; @K4} cP  
try{ J0d +q!  
oSavedFile.write(b,nStart,nLen); x\3 ` W  
n = nLen; 89`AF1  
} _<pG}fmR  
catch(IOException e) |ng[s6uf  
{ 9C|T/+R  
e.printStackTrace (); 9 ?MOeOV8  
} WB6g i2  
gSZ NsiH  
>kz5azV0  
return n; V/"0'H\"1  
} 6xk"bIp  
#c+N}eX{  
QMy;?,  
} *ErTDy(   
aZ*b"3  
U[U$1LSS  
/* +'uF3- +WY  
**SiteInfoBean.java 6M"J3\ x  
*/ dvyE._/v  
package NetFox; L(`^T`  
Yah3I@xGy  
@o9EX }  
public class SiteInfoBean { [ ]3xb`<&  
#mk#&i3"k  
hB P]^~(  
private String sSiteURL; //Site's URL 7R7g$  
private String sFilePath; //Saved File's Path qAR~js`5  
private String sFileName; //Saved File's Name "Z &qOQg%3  
private int nSplitter; //Count of Splited Downloading File ^yy\CtG  
O4 \GL  
|rW}s+Kcr  
public SiteInfoBean() "SLN8x49(  
{//nSplitter的缺省值为5 w]tv<U={  
//default value of nSplitter is 5 ^w8H=UkP!+  
this("","","",5); u$t*jw\fHg  
} LP@Q8{'  
XXuU@G6Z7$  
cX7xG U  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L.U [eH  
{ gWy 2$)  
sSiteURL= sURL; 87~. |nu  
sFilePath = sPath; ukS@8/eJ  
sFileName = sName; Bwb3@vNA  
this.nSplitter = nSpiltter; %L/Wc,My  
ppb]RN|)  
kL*Q})  
} S;+bQ.  
*N\U{)b\  
zclt2?  
public String getSSiteURL() jGR_EE  
{ 0u'2f`p*  
return sSiteURL; TQE3/IL  
} \{{B57/Isq  
o6xl,T%  
>AN`L`%2  
public void setSSiteURL(String value) U lj2 Py}  
{ i&mu=J[  
sSiteURL = value; Z=8 25[p  
} 5SR 29Z[  
;]Y.2 J  
ZS>}NN  
public String getSFilePath() k-e_lSYk&c  
{ /Wg$.<!5 }  
return sFilePath; g@MTKqs  
} {n$9o  
eW\7X%I  
e_k1pox]l  
public void setSFilePath(String value) fcnbPO0M  
{ a3R#Bg(  
sFilePath = value; u;!CQ w/  
} Nf-IDK  
9y.C])(2  
#jA|04w  
public String getSFileName() ,GVHwTZ0`  
{ RBt"7'  
return sFileName; /}#z/m@bN  
} S@N&W&W#~  
3|9) A+,#  
=;dupz\7  
public void setSFileName(String value) n U$Lp`  
{ aina6@S  
sFileName = value; &IXr*I  
} sKn>K/4JZ  
:E4i@ O7%  
e#FaK^V  
public int getNSplitter() =]-!  
{ c!{.BgGN  
return nSplitter; pR`.8MMc8  
} F~W*"i+EZ  
,dzbI{@6  
2#T|+mKxZM  
public void setNSplitter(int nCount) r'{pTgm#  
{ kRSu6r9  
nSplitter = nCount; 'PV,c|f>  
} f[%\LHq  
} P0' ;65  
KkJcH U  
p7zHP  
/* :Gy .P  
**Utility.java ;Jv)J3y  
*/ lG fO  
package NetFox; I4qzdD  
UupQ* ,dJ  
)c]GgPH  
public class Utility {  Gp@Y=mU  
1MfRF v  
| 2p\M?@  
public Utility() sl |S9Ix  
{ o)"}DeV$&  
zr84%_^  
KW+^9&lA  
} F4kU) i  
&rcr])jg[  
//线程睡眠 W 86S)+h  
public static void sleep(int nSecond) 'qQ DM_+  
{ 9XobTi3+'  
try{ ?D57HCd`n  
Thread.sleep(nSecond); \m5:~,p=  
} <C# s0UX  
catch(Exception e) 1PLKcU  
{ I>L lc Y  
e.printStackTrace (); jqb,^T|j;m  
} Zu&trxnNf[  
} xhg{!w  
.7~Kfm@2  
//日志 U:_T9!fG  
public static void log(String sMsg) 9dqD(S#C;"  
{ 2=F_<Jh|+  
System.err.println(sMsg); I?bL4u$\  
} %b@>riR(y  
e!eWwC9u  
rLh490@  
public static void log(int sMsg) ,_\h)R_  
{ <0v'IHlZ8  
System.err.println(sMsg); .N/4+[2p(  
} /~g M,*  
} <pK; D  
gJ vc<]W8!  
2kCJqyWy  
/* iLv"ZqGrw  
**TestMethod.java ^4 es  
*/ 5>h2WL  
package NetFox; //H+S q66  
_or$^.='  
X903;&Cim  
public class TestMethod { _I5p 7X  
.u W_(Rqg  
gj6"U {D  
public TestMethod() yMX4 f  
{ ///xx/weblogic60b2_win.exe %4n=qK9T 5  
try{ q.Z0Q  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Nm OQ7T  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); GbB&kE3KP  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6kIq6rWF9  
fileFetch.start(); t MA  
} IQ2<Pinv  
catch(Exception e){e.printStackTrace ();} ELY$ ]^T  
JK,#dA#  
RR`?o\  
} HV>|f'45  
{) Y &Vr5  
G=yQYsC$  
public static void main(String[] args) ^9cqT2:t  
{ P 3lN ns3  
new TestMethod(); 4fP>;9[F  
} Fo~C,@/Qt  
} 2<u vz<B  
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