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http断点续传简单实现(java)

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/* wYJ.F  
**SiteFileFetch.java k!K}<sX2  
*/ *;wPAQE  
package NetFox; "Fu*F/KW  
import java.io.*; <$LVAy"RD  
import java.net.*; d3AOuVUf  
:Uf\r `a9  
Q0I22?  
public class SiteFileFetch extends Thread { d([NU;  
8=H!&+aGh  
0S0 ?\r  
SiteInfoBean siteInfoBean = null; //文件信息Bean JZP>`c21y]  
long[] nStartPos; //开始位置 9GuG"^08  
long[] nEndPos; //结束位置 hGx)X64Mw  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ((TiBCF4  
long nFileLength; //文件长度 |>(;gr/5(  
boolean bFirst = true; //是否第一次取文件 jX79Nm|  
boolean bStop = false; //停止标志  `k/hC  
File tmpFile; //文件下载的临时信息 w^?uBeqR  
DataOutputStream output; //输出到文件的输出流 iXt >!f*  
{i)k#`  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) MMglo3  
public SiteFileFetch(SiteInfoBean bean) throws IOException jiMI&cl  
{ ^9 gFW $]  
siteInfoBean = bean; *4;MO2g  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); VQO6!ToKY  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); *wcb5p  
if(tmpFile.exists ()) o[W7'1O  
{ UW*[)yw]  
bFirst = false; /ov&h;  
read_nPos(); FV>LD% uu  
} :4PK4D s7  
else < ) L'h  
{ gN|[n.W4  
nStartPos = new long[bean.getNSplitter()]; f\FubL  
nEndPos = new long[bean.getNSplitter()]; 9pD=E>4?#  
} uI^E9r/hB  
Bkvh]k;F8  
qh!2dj  
 &y/  
} lV/-jkR  
GU\}}j]  
#y }{ 'rF?  
public void run() FOxMt;|M  
{ sHx>UvN6  
//获得文件长度 pJ7M.C!  
//分割文件 {#aW")x^#  
//实例FileSplitterFetch > Q+Bw"W<  
//启动FileSplitterFetch线程 ]42bd  
//等待子线程返回 {k=H5<FV  
try{ *Y'@|xf*  
if(bFirst) Mvq5s+.  
{ sf\p>gb  
nFileLength = getFileSize(); 47b=>D8  
if(nFileLength == -1) g/&`NlD  
{ *6 oQW  
System.err.println("File Length is not known!"); m0+X 109  
} :|3n`,  
else if(nFileLength == -2) O)78 iEXi|  
{ _Gv[ D  
System.err.println("File is not access!"); I;]Q}SUsm  
} S3rN]!B+  
else <RfPd+</  
{ rnvKfTpZDU  
for(int i=0;i<nStartPos.length;i++) @0cQ4}  
{ ?YzOA${  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); og<mFbqkq7  
} C 7)w8y  
for(int i=0;i<nEndPos.length-1;i++) (he cvJ  
{ 7/nnl0u8  
nEndPos = nStartPos[i+1]; $Cw> z^}u  
} !e?g"5r{Bv  
nEndPos[nEndPos.length-1] = nFileLength; t{n|!T&  
} D7.|UG?G  
} 6KuB<od  
4<b=;8  
f$vWi&(  
//启动子线程 a[;TUc^I1F  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bkfwsYZx  
for(int i=0;i<nStartPos.length;i++) =~M%zdIXv  
{ I^>m-M.  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(),  II;fBcXF  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), / 4P+  
nStartPos,nEndPos,i); Gq_rZo(@  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -F.A1{l[.  
fileSplitterFetch.start(); '|mVY; i[  
} UX3 ]cr  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /,v>w,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wg<UCmfu!  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YY~BNQn6d  
nEndPos = " + nFileLength); \mRRx#-r%  
// fileSplitterFetch[nPos.length-1].start(); n]$50_@  
nA:\G":\y  
J ik+t\A  
//等待子线程结束 T=6fZ;7  
//int count = 0; K?[*9Q'\  
//是否结束while循环 >*#clf;@p  
boolean breakWhile = false; WqX#T  
i7g+8 zd8d  
HAa2q=  
while(!bStop) bvY'=   
{ !QK ~l  
write_nPos(); ;8z40cD  
Utility.sleep(500); i[obQx S94  
breakWhile = true; U40adP? a  
t?J Y@hT*  
bvZTB<rA  
for(int i=0;i<nStartPos.length;i++) rv>K0= t0  
{ )NG{iD{_]  
if(!fileSplitterFetch.bDownOver) !vNZ- }  
{ 'BY{]{SL  
breakWhile = false; Wez"E2J`  
break; ?M'_L']N[  
} t[Dg)adc  
} ,VK! 3$;|  
if(breakWhile) Ul@ Jg    
break; '\yp}r'u  
0Y7b$~n'Y  
VO"f=gFg  
//count++; WR'm<u  
//if(count>4) ub^v ,S8O  
// siteStop(); 3m1]Ia -9  
} (x7AV$N  
P} =eR  
? U~}uG^  
System.err.println("文件下载结束!"); q}Wd`>VDR  
} 5r1{l%?  
catch(Exception e){e.printStackTrace ();} 2p3ep,  
} +^!;J/24  
rG7S^,5o  
mQ#E{{:H+  
//获得文件长度 CS[[TzC=5  
public long getFileSize() P $4h_dw  
{ V'vDXzk\  
int nFileLength = -1; B/#tR^R  
try{  q0Rd^c  
URL url = new URL(siteInfoBean.getSSiteURL()); OE,uw2uaT  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !_{2\ &  
httpConnection.setRequestProperty("User-Agent","NetFox"); ('1k%`R%  
&mebpEHUG7  
ppcuMcR{  
int responseCode=httpConnection.getResponseCode(); [5&zyIi  
if(responseCode>=400) Q8:`;W  
{ 1S !<D)n  
processErrorCode(responseCode); hR;J#w  
return -2; //-2 represent access is error Mv9q-SIc[  
} ]KX _a1e  
<a>\.d9#)7  
$,+'|_0yM  
String sHeader; b}P5*}$:9"  
cp|&&q  
![O@{/  
for(int i=1;;i++) IEb"tsel  
{ K*&?+_v :  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]V9z)uz  
//Utility.log(in.readLine()); gemjLuf  
sHeader=httpConnection.getHeaderFieldKey(i); RfPRCIo  
if(sHeader!=null) I"*;fdm  
{ }@Mx@ S  
if(sHeader.equals("Content-Length"))  (`0dO8  
{ @d5G\1(%  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z?~W]PWiZ  
break; i*16k dI.  
} lLuAZoH  
} =6#tJgg8  
else 2Z]<MiAxD  
break; .HTX7mA3  
} 9T*%CI  
} Rg*zUfu5%o  
catch(IOException e){e.printStackTrace ();} ?H9F"B$a  
catch(Exception e){e.printStackTrace ();} G-FTyIP>'  
r30t`o12i  
 *,9.Bx*  
Utility.log(nFileLength); 2i);2>HLG  
phIEz3Fu/  
m.~&n!1W*`  
return nFileLength; $mA+ 4ISK  
} B7Um G)C  
h-VpX6  
q9n0bw^N  
//保存下载信息(文件指针位置) 51oZ w%os=  
private void write_nPos() 5BKmp-m  
{ y%T5"p$,  
try{ {b@rQCre7  
output = new DataOutputStream(new FileOutputStream(tmpFile)); amI$0  
output.writeInt(nStartPos.length); &lYKi3}x  
for(int i=0;i<nStartPos.length;i++) Zp|LCE"  
{ "i$uV3d  
// output.writeLong(nPos); }vOUf# ^k  
output.writeLong(fileSplitterFetch.nStartPos); _q([k_4h  
output.writeLong(fileSplitterFetch.nEndPos); ) Qve[O  
} <@C Bc:j0  
output.close(); 9E{Bn#  
} eK"B.q7  
catch(IOException e){e.printStackTrace ();} Qi^MfHW  
catch(Exception e){e.printStackTrace ();} Vy = fm  
} ]y 6`9p  
fTi,S)F'  
Xq&x<td  
//读取保存的下载信息(文件指针位置) zE V J  
private void read_nPos() 8uME6]m i  
{ @URLFMFi  
try{ nbYkr*: "t  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); P=& Je?  
int nCount = input.readInt(); *VT@  
nStartPos = new long[nCount]; }I7/FqrD  
nEndPos = new long[nCount]; ;??wLNdf-  
for(int i=0;i<nStartPos.length;i++) Mj$dDtw  
{ WNT m  
nStartPos = input.readLong(); vx=I3o  
nEndPos = input.readLong(); n5_r 3{  
} pt8X.f,iA  
input.close(); zx\N^R;Jq  
} :>lica_  
catch(IOException e){e.printStackTrace ();} v>Il #  
catch(Exception e){e.printStackTrace ();} |dNtM^  
} ZNPzQ:I@  
/2oTqEqaV  
vCwDE~  
private void processErrorCode(int nErrorCode) ?,r bD 1  
{ "fLGXbNQ  
System.err.println("Error Code : " + nErrorCode); [d!C6FT  
} /qF7^9LtaY  
O?@1</r^  
{xt<`_R  
//停止文件下载 yy?|q0  
public void siteStop() ] K7>R0  
{ ?Gl'-tV  
bStop = true; EU,4qO  
for(int i=0;i<nStartPos.length;i++) 6<H[1PI`,G  
fileSplitterFetch.splitterStop();  e4NT  
G*BM'^0+  
e#k9}n^+  
} <9bQAyL9  
} c>K/f7  
//负责部分文件的抓取 Xj$J}A@  
**FileSplitterFetch.java |aN0|O2  
*/ fD q, )~D  
package NetFox; kETA3(h'  
bi!4I<E>k  
<Q=ES,M  
import java.io.*; ^e8R 43w:!  
import java.net.*; 5h[u2&;G  
p)ta c*US  
QN-n9f8  
public class FileSplitterFetch extends Thread { c}mJ6Pt  
:LVM'c62c>  
&+`l $h  
String sURL; //File URL oO @6c%  
long nStartPos; //File Snippet Start Position GT%V,OJ  
long nEndPos; //File Snippet End Position MvY0?!v  
int nThreadID; //Thread's ID U=XaI%ZM)  
boolean bDownOver = false; //Downing is over *D<S \6=  
boolean bStop = false; //Stop identical LF%1)x  
FileAccessI fileAccessI = null; //File Access interface (W+9 u0Zq  
*wp'`3y}  
!U>"H8}dv  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1s\10 hK1c  
{ /db?ltb  
this.sURL = sURL; ~1Tz[\H#R  
this.nStartPos = nStart; T-&CAD3 ,O  
this.nEndPos = nEnd; ~N[hY1}X[  
nThreadID = id; |k&.1NkZ  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -7ct+3"J  
} /_,~dt  
j %TYyL-  
=[{Pw8['  
public void run() q22cp&gmX  
{ Hh;w\)/%j  
while(nStartPos < nEndPos && !bStop) }(E6:h;}~  
{ '! 1ts@  
;~]&$2sk  
DHt 8 f  
try{ zwU8iVDe  
URL url = new URL(sURL); (53dl(L?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *"fg@B5  
httpConnection.setRequestProperty("User-Agent","NetFox"); @+1E|4L1vf  
String sProperty = "bytes="+nStartPos+"-"; .ET;wK  
httpConnection.setRequestProperty("RANGE",sProperty); d@At-Z~M  
Utility.log(sProperty); ![Ip)X OG  
}C*o;'o5G  
K- }k-S  
InputStream input = httpConnection.getInputStream(); P+}qaup  
//logResponseHead(httpConnection); q'(WIv@  
!+ uMH!  
'dWJ#9C  
byte[] b = new byte[1024]; #]lUJ &M}e  
int nRead; &K>]!yn   
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X""'}X|O  
{ oTI*mGR1Z  
nStartPos += fileAccessI.write(b,0,nRead); 7v,>sX  
//if(nThreadID == 1) F5 LQgK-z  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iqy}|xAU  
} +crAkb}i  
`zzX2R Je  
mApn(&  
Utility.log("Thread " + nThreadID + " is over!"); x(]s#D!)  
bDownOver = true; ~;eWQwD  
//nPos = fileAccessI.write (b,0,nRead); iLmU|jdE  
} jLQjv  
catch(Exception e){e.printStackTrace ();} e_1mO 5z  
} 1 9 k$)m  
} n[4Nu`E9  
CPVKz   
c6c^9*,V  
//打印回应的头信息 OM4s.BLY  
public void logResponseHead(HttpURLConnection con) /kw4":{]  
{ yN>"r2   
for(int i=1;;i++) K,IOD t  
{ N7oMtlvL[w  
String header=con.getHeaderFieldKey(i); J~_p2TZJ\3  
if(header!=null) J.<eX=<  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l*v([@A\  
Utility.log(header+" : "+con.getHeaderField(header)); =rBFMTllM  
else 7Ck;LF}>0  
break; =\XAD+  
} 'oT}jI  
} e-e{-pB6  
5)nv  
}qKeX4\-  
public void splitterStop() >`{i[60r  
{ Tby+Pd;  
bStop = true; (VOKa  
} mlVv3mVyR<  
@\"*Z&]8z0  
chd${ j  
} }MIH{CMH  
6\TstY3  
)F~>  
/* [CUJA  
**FileAccess.java ?1N0+OW   
*//文件访问(定位,写) y:42H tS  
package NetFox; '^/E2+  
import java.io.*; Bw_Ih|y,w  
]~K&mNo  
)K?GAj]Pq  
public class FileAccessI implements Serializable{ `PW=_f={  
he+[  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9Np0<e3p  
RandomAccessFile oSavedFile; |wLQ)y*  
long nPos; cbwzT0  
 *$cp"  
:jUuw:\  
public FileAccessI() throws IOException YAPD7hA  
{ /GXO2zO  
this("",0); 9{TOFjsF  
} ReE3742@  
3?%kawO&  
<>e<Xd:77{  
public FileAccessI(String sName,long nPos) throws IOException ks r5P~  
{ #!5Nbe  
oSavedFile = new RandomAccessFile(sName,"rw"); e`~q ;?:  
this.nPos = nPos; WuNu}Ibl}m  
oSavedFile.seek(nPos); Dw #&x/G  
} e{} o:r  
b?Jm)  
-$0S#/)Z  
public synchronized int write(byte[] b,int nStart,int nLen) <Z__Q  
{ ZH}NlEn  
int n = -1; sY6'y'a95  
try{ h4qR\LX  
oSavedFile.write(b,nStart,nLen); |M?HdxPa  
n = nLen; F0JFx$AoD  
} J6%op{7/  
catch(IOException e) 1(?J>{-lw  
{ d+;wDu   
e.printStackTrace (); Q&#:M>!|  
} Kje+Niz7  
amSyGQ2  
i3"sAr P"|  
return n; g.]'0)DMW  
} TkBBHg;  
;MMFF{  
UQR"wUiiV  
} UZ!hk*PF  
bVx]r[  
IYO,/ kbf  
/* V[mQ;:=  
**SiteInfoBean.java etoE$2c  
*/ iN*>Z(b"  
package NetFox; PGKXzp'  
1A)~Y   
uUe\[-~  
public class SiteInfoBean { G8s`<:9*  
0/6&2  
mqHt%RX  
private String sSiteURL; //Site's URL kYs|")isj  
private String sFilePath; //Saved File's Path AWDjj\Q4  
private String sFileName; //Saved File's Name _tk5?9Ykn  
private int nSplitter; //Count of Splited Downloading File XZInu5(  
cP1jw%3P  
k:TfE6JZ  
public SiteInfoBean() SRTpE,  
{//nSplitter的缺省值为5 [:QMnJ  
//default value of nSplitter is 5 U. aa iX7  
this("","","",5); *X\c $ =*  
} W.|6$hRl)  
i njmP9ed  
)^\='(s  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;Kf|a}m-  
{ vdm?d/0(^  
sSiteURL= sURL; sb @hGS  
sFilePath = sPath; JB+pFBeY  
sFileName = sName; 9NP l]iA)  
this.nSplitter = nSpiltter; Tv$7aVi!  
R`Lm"5w  
j;v%4G  
} $3TTHS o  
i .N1Cvp&  
!_9$[Oq~  
public String getSSiteURL() )DmiN^:  
{ B@]7eVo  
return sSiteURL; `I8^QcP  
} ymZ/(:3_  
{ +2cRr.  
tTGK25&  
public void setSSiteURL(String value) >bN~p  
{ <L~xR5  
sSiteURL = value; sAoM=n}!  
} zy[=OX+  
9i}D6te  
(U_Q7hja?  
public String getSFilePath() bUN,P"  
{ @q/1m~t  
return sFilePath; pK9^W T@  
} 2?T:RB}  
X u):.0I  
dz|*n'd  
public void setSFilePath(String value) pq3  A%|  
{ wzPw; xuG  
sFilePath = value; igrog  
} X|`,AK Jit  
"Y]ZPFh#.  
EQ7n'Wqq  
public String getSFileName() 5j,qAay9  
{ CS\tCw\Y  
return sFileName; C 94@YWs  
} nV3 7` I  
Tr0V6TS7  
&H&P)Px*_  
public void setSFileName(String value) !>< %\K  
{ r ` &|)Hx  
sFileName = value; yim$y, =d  
} 50ew/fZj|  
aNC,ccm  
:bRR(sP  
public int getNSplitter() Kk>qgi$  
{ 5\0.[W{^  
return nSplitter; _IV@^v  
} )v=G}j^  
cXcx_-  
(VaN\+I:T  
public void setNSplitter(int nCount) RVnyl`s  
{ SMO%sZ]  
nSplitter = nCount; 2 dD<]  
} A dEbyL  
} @JEmybu  
CQHp4_  
PdH`_/6  
/* 4spaw?j  
**Utility.java nRB>[lG  
*/ 4 l}M i  
package NetFox; BZ+ mO  
As~p1%nok  
P5}[*k%DQw  
public class Utility { < }wAP_y  
n [Xzo}  
Ik5jwfz  
public Utility() 5o| !f  
{ wUCDJY:,1  
:"P hkR  
O)xEF~DaD  
} GHJ=-9{YL  
< mK  
//线程睡眠 ' ?G[T28  
public static void sleep(int nSecond) ,(0XsBL  
{ [k~+(.2I  
try{ ]Ec[")"kT  
Thread.sleep(nSecond); =x0"6gTz>  
} !@Sf>DM"  
catch(Exception e) r\n h.}s  
{ VuMDV6^Z  
e.printStackTrace (); sRyw\v-=P  
} 2Z`$  
} "56?/ jF  
+Bq}>  
//日志 ]X: rby$  
public static void log(String sMsg) R_Gq8t$  
{ #1't"R+3M  
System.err.println(sMsg); cCh5Jl@Z  
} an=+6lIl  
lDJd#U'V  
a^XTW7]r  
public static void log(int sMsg) ;Co[y=Z  
{ wEfz2Eq  
System.err.println(sMsg); C*s0r;  
} rF'^w56  
} R'9@A\7#  
IN|i)?r h  
,-7/]h,l  
/* c_z/At;4  
**TestMethod.java L_gsG|xX  
*/ aC,vh1")F  
package NetFox; 0"kE^=  
QK?2E   
?St=7a(D  
public class TestMethod { )qyx|D  
~f=6?5.wa  
dx13vZ3[U  
public TestMethod() XW~ BEa  
{ ///xx/weblogic60b2_win.exe tT* W5  
try{ YZBzv2'\x  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 64!ame}n+  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W\>^[c/  
SiteFileFetch fileFetch = new SiteFileFetch(bean); HhWwc#B  
fileFetch.start(); }r~v,KDb  
} ll(e,9.D  
catch(Exception e){e.printStackTrace ();}  mF*?e/  
/h7>Z9T  
Y*kh$E%<#  
} qXU:A-IdIl  
Z9"{f)T  
\2R`q*a+  
public static void main(String[] args) b 5F4+  
{ 5xMA~I0c  
new TestMethod(); V<HOSB7  
} AU\xNF3  
} t*Vao  
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