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http断点续传简单实现(java)

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/* .P aDR |!  
**SiteFileFetch.java T3@2e0u )  
*/ >Zs!  
package NetFox; ;Vs2 e  
import java.io.*; pu]U_Ll@  
import java.net.*; `bfUP s  
wjwCs`  
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public class SiteFileFetch extends Thread { R[j?\#  
Z4Dx:m-  
&K[sb%  
SiteInfoBean siteInfoBean = null; //文件信息Bean *$BUow/>  
long[] nStartPos; //开始位置 _.Hj:nFHz  
long[] nEndPos; //结束位置 `;+x\0@<  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Zk((VZ(y  
long nFileLength; //文件长度 R20 .dA_N  
boolean bFirst = true; //是否第一次取文件 G3io!XM)D  
boolean bStop = false; //停止标志 [,,@>nyD  
File tmpFile; //文件下载的临时信息 $"W[e"Q  
DataOutputStream output; //输出到文件的输出流 ]tN)HRk1  
N6"sXw m  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) zGR, }v%%  
public SiteFileFetch(SiteInfoBean bean) throws IOException @Kz,TP!%A  
{ ">CRFee0  
siteInfoBean = bean; ; F'IS/ttX  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); gv>DOez/  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); jVd`J  
if(tmpFile.exists ()) F:T(-,  
{ el*|@#k}  
bFirst = false; V 97ORI  
read_nPos(); Mf#@8"l  
} 1F,U^O  
else Ig}hap]G  
{ 5=I({=/>  
nStartPos = new long[bean.getNSplitter()]; i/+^C($'f  
nEndPos = new long[bean.getNSplitter()]; Os'E7;:1h  
} H=C~h\me?  
x-k-Pd  
.1RQ}Ro,<  
XYuX+&XW/  
} *6` ^8Y\  
jmwN1Se>  
!DFTg 4xb  
public void run() P"^Yx8L#  
{  Y4 z  
//获得文件长度 j0}wv~\  
//分割文件 qsW&kW~  
//实例FileSplitterFetch  ~d eS*  
//启动FileSplitterFetch线程 '1LN)Yw  
//等待子线程返回 wg%Z  
try{ +bLP+]7oZ  
if(bFirst) =o~+R\1ux+  
{ 6Q7=6  
nFileLength = getFileSize(); nt$P A(Y  
if(nFileLength == -1) dxAGO(  
{ ,$:u^;V(  
System.err.println("File Length is not known!"); .O1w-,=  
} GqL&hbpi  
else if(nFileLength == -2) 5@%Gq)z5  
{ `aAE4Ry?  
System.err.println("File is not access!"); Zt! $"N.,  
} e8("G[P >  
else Z,2?TT|p  
{ @[9  
for(int i=0;i<nStartPos.length;i++) 'RKpMdoz  
{ ,]wQ]fpt  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); xaVX@ 3r.3  
} Kt*fQ `9  
for(int i=0;i<nEndPos.length-1;i++) 3]?='Qq.(  
{ aC2Vz9e  
nEndPos = nStartPos[i+1]; 01-rBto$  
} jFdgFK c)  
nEndPos[nEndPos.length-1] = nFileLength; OP=brLGu0  
} x}K|\KXy  
} HJN GO[*g  
1?H; c5?d&  
NzyEsZ]$  
//启动子线程 "=s}xAM|A  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pP":,8Q{  
for(int i=0;i<nStartPos.length;i++) ^g6v#]&WA  
{ KJoa^e;~  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hbJy<e1W  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =t-Ud^3  
nStartPos,nEndPos,i); yg'CL/P  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W`9{RZ'  
fileSplitterFetch.start(); vw!7f|Pg ~  
} gPB=Z!  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,= ApnNUgX  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S;#:~?dU  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q;nAq%  
nEndPos = " + nFileLength); 13/,^?  
// fileSplitterFetch[nPos.length-1].start(); 4bGvkxZo`$  
plB8iN`x<  
wsB-( 0-  
//等待子线程结束 {l$)X  
//int count = 0; A4@z+ebb l  
//是否结束while循环 S y <E@1  
boolean breakWhile = false; ty['yV-;a  
`PtB2,?  
dNf9,P_}  
while(!bStop) :2c(.-[`  
{ 6/L[`n"G  
write_nPos(); 4h!yh2c..  
Utility.sleep(500); A,EG0yb  
breakWhile = true; 8Gy]nD  
Uz_ob9l<#H  
D.{vuftu  
for(int i=0;i<nStartPos.length;i++) jW8ad{  
{ 8/R$}b><  
if(!fileSplitterFetch.bDownOver) P{K\}+9F   
{ 5 ,MM`:{{  
breakWhile = false; [rcM32  
break; :!Q(v(M  
} JJ)  
} 4K:Aqqhds  
if(breakWhile) Cj~e` VRhk  
break; W895@  
e"^WXP.t&  
/'DAB**  
//count++; +sn0bi/rG  
//if(count>4) v2]N5  
// siteStop(); OCdX'HN5Y  
} ;U?=YSHk7  
W#g!Usf:/  
"B__a(  
System.err.println("文件下载结束!"); }o!b3*#  
} WP\kg\o  
catch(Exception e){e.printStackTrace ();} ?E!M%c@,  
} 7CR#\&h`  
+pq=i  
\\ R<HuTY  
//获得文件长度 W7|nc,i0\  
public long getFileSize() _X?_|!;J  
{ [^a7l$fmi  
int nFileLength = -1; #B?lU"f8q^  
try{ Adiw@q1&  
URL url = new URL(siteInfoBean.getSSiteURL()); |qQ6>IZ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C3=0 st$  
httpConnection.setRequestProperty("User-Agent","NetFox"); <Sd ef^  
(kX:@9Pn  
j-/$e,xX  
int responseCode=httpConnection.getResponseCode(); uYlyU~M:D  
if(responseCode>=400) m=h/A xW  
{ !sI^Lh,Y  
processErrorCode(responseCode); jt6_1^  
return -2; //-2 represent access is error 9wfE^E1  
} ?Mo)&,__  
= =pQ V[  
)g8Kicox5  
String sHeader; ;>ml@@Z  
b (H J|  
wG s'qL"z  
for(int i=1;;i++) _M8'~$Sg  
{ EVqqOp1$v4  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); au=@]n#<(  
//Utility.log(in.readLine()); W^HE1Dt]  
sHeader=httpConnection.getHeaderFieldKey(i); 6X'0 T}  
if(sHeader!=null) 7fWZ/;p  
{ 8H};pu2  
if(sHeader.equals("Content-Length")) e:MbMj6`  
{ % mPv1$FH  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'e<8j  
break; FU*q9s`  
} fS'` 9  
} \ 6taC  
else {l/`m.Z  
break; OD Ry  
} 2H8\P+  
} cna%;f.  
catch(IOException e){e.printStackTrace ();} M).CyY;bm  
catch(Exception e){e.printStackTrace ();} Zr6.Nw  
g*_n|7pB  
}vP(SF 6  
Utility.log(nFileLength); >@G"*le*)  
y~OP9Tg  
mIrN~)C4\  
return nFileLength; FnOa hLS  
} >U\P^yU  
1\lZ&KX$i  
<ir]bQT  
//保存下载信息(文件指针位置) By[M|4a  
private void write_nPos() 5(1c?biP&  
{ :>ca).cjac  
try{ >*B59+1P  
output = new DataOutputStream(new FileOutputStream(tmpFile)); +,7vbs3  
output.writeInt(nStartPos.length); _I,GH{lhI  
for(int i=0;i<nStartPos.length;i++) l%0-W  
{ Y0Tw:1a  
// output.writeLong(nPos); uTO%O}D N  
output.writeLong(fileSplitterFetch.nStartPos); M;AvOk|&  
output.writeLong(fileSplitterFetch.nEndPos); pIpdVKen  
} M|@@ LJ'  
output.close(); ] NW_oRH  
} Hv' OO@z  
catch(IOException e){e.printStackTrace ();} +S#Xm4  
catch(Exception e){e.printStackTrace ();} #_3ZF"[zq  
} /`#JM  
{ktwX\z  
SuI^8^f=  
//读取保存的下载信息(文件指针位置) =%I;Y& K  
private void read_nPos() -#4QY70H t  
{ 3 Sf':N`u  
try{ ;U a48pSv  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?Ec{%N%  
int nCount = input.readInt(); 1x##b [LC  
nStartPos = new long[nCount]; /Wl8Jf7'  
nEndPos = new long[nCount]; rOYYZ)Qw  
for(int i=0;i<nStartPos.length;i++) hZo  f  
{ 7#Fcn  
nStartPos = input.readLong(); L|b[6[XTHL  
nEndPos = input.readLong(); 2*gB~Jn4  
} p,(W?.ZDN?  
input.close(); c*R\fQd  
} S5H}   
catch(IOException e){e.printStackTrace ();} h~._R6y  
catch(Exception e){e.printStackTrace ();} I;?PDhDb  
} nHF~a?|FT  
hVFZQJ?cv  
211T}a  
private void processErrorCode(int nErrorCode) I 5ZDP|  
{ B=r+ m;(  
System.err.println("Error Code : " + nErrorCode); |{,c2 Ck:N  
} TB<$9FCHK  
Ne3YhCC>  
K2v[_a~@  
//停止文件下载 ?-0, x|ul  
public void siteStop() E 8$S0u;`  
{ d|W=_7 z  
bStop = true; ,E%O_:}R  
for(int i=0;i<nStartPos.length;i++) {C8IYBm  
fileSplitterFetch.splitterStop(); *].qm g%  
j]-_kjt  
>-3>Rjo>  
}  -V"W  
} fb[lL7  
//负责部分文件的抓取 Zrgv*  
**FileSplitterFetch.java @1bl<27  
*/ G%!i="/9  
package NetFox; _2<UcC~  
4Xwb`?}-  
nHZhP4W  
import java.io.*; U ){4W0  
import java.net.*; 3=Uyt  
?Ycl!0m  
[yc7F0Aw  
public class FileSplitterFetch extends Thread { =C|^C3HK  
xwwL  
$n47DW &  
String sURL; //File URL b53s@7/mq  
long nStartPos; //File Snippet Start Position :}#j-ZCC"  
long nEndPos; //File Snippet End Position zyP/'X_~:  
int nThreadID; //Thread's ID 7.)_H   
boolean bDownOver = false; //Downing is over 3'0Jn6(  
boolean bStop = false; //Stop identical tef>Py  
FileAccessI fileAccessI = null; //File Access interface D=.Ob<m`Z  
k f|J  
i]@k'2N  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException NweGK  
{ im)r4={ 9  
this.sURL = sURL; (WY9EJ<s,  
this.nStartPos = nStart; v:w^$]4  
this.nEndPos = nEnd; NMC0y|G  
nThreadID = id; V_n tS& 2o  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =@hCc  
} PJ<qqA`!  
4? rEO(SZ  
1M55!b  
public void run() |(,{&\  
{  =Uo*-EH  
while(nStartPos < nEndPos && !bStop) utn,`v   
{ 3rJ LLYR  
,I]]52+?4  
tqpi{e  
try{ 0G Q8} r  
URL url = new URL(sURL); 2#/sIu-L  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X(8LhsP  
httpConnection.setRequestProperty("User-Agent","NetFox"); iO18FfM_  
String sProperty = "bytes="+nStartPos+"-"; -r~9'aEs  
httpConnection.setRequestProperty("RANGE",sProperty); <*/Z>Z_c2  
Utility.log(sProperty);  b=Ektq  
@LS%uqs  
J*6B~)Sp@  
InputStream input = httpConnection.getInputStream(); XgeUS;qtta  
//logResponseHead(httpConnection); 7xWJw  
)"2eN3H/  
,4-],~T  
byte[] b = new byte[1024]; x'6i9]+r  
int nRead; Q]RE,ZZ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) DFRgn  
{ id`RscV]  
nStartPos += fileAccessI.write(b,0,nRead); WYcZD_  
//if(nThreadID == 1) (hKjr1s  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jzWgyI1b  
} #~qza ETv,  
fwUF5Y  
$DnR[V}rR!  
Utility.log("Thread " + nThreadID + " is over!"); WOeLn[  
bDownOver = true; 1L?W+zMO  
//nPos = fileAccessI.write (b,0,nRead); 8A-*MU`+  
} 9.#")%_p  
catch(Exception e){e.printStackTrace ();} J^PFhu  
}  R; &k/v  
} hD,|CQ  
D+q z`  
[;:ocy  
//打印回应的头信息 lKqFuLHwF  
public void logResponseHead(HttpURLConnection con) iex]J@=e  
{ x[+bLlb  
for(int i=1;;i++) ,&* BhUC  
{ Y OvhMi  
String header=con.getHeaderFieldKey(i); 2jkma :$'  
if(header!=null) )}_}D +2  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l>(*bb1}b  
Utility.log(header+" : "+con.getHeaderField(header)); bhsCeH  
else #~w~k+E4  
break; g~9b_PY9  
} $d.Dk4.ed  
} >-w# &T &K  
h^14/L=|  
qc3,/JO1  
public void splitterStop() @ @(O##(7  
{ T5:xia>8O  
bStop = true; 7pnlS*E.  
} @2_ E9{T  
L(1} PZ  
K]dR%j  
} 45jImCm  
:n%&  
$_\x}`c~.  
/* fZnq5rTk"  
**FileAccess.java 0[7"Lhpd  
*//文件访问(定位,写) XCXX(8To0=  
package NetFox; "zqa:D26  
import java.io.*; [l<&eI&ln  
A2P.5EN  
}"kF<gG1  
public class FileAccessI implements Serializable{ dAM]ZR<  
[ThAv Q_$  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L EFLKC  
RandomAccessFile oSavedFile; xv%]g= Q  
long nPos; iYlkc  
:<5jlpV(  
6%wlz%Fp  
public FileAccessI() throws IOException "t-9q  
{ W!+=`[Ff  
this("",0); ;Uy}(  
} r-]%R:U*  
)?6%d  
={o)82LV  
public FileAccessI(String sName,long nPos) throws IOException lB#7j  
{ 5as5{"l  
oSavedFile = new RandomAccessFile(sName,"rw"); q; C6ID`  
this.nPos = nPos; OF-g7s6VH  
oSavedFile.seek(nPos); sl P>;  
} HoeW6UV  
J*Cf1 D5!  
H"?Ndl:  
public synchronized int write(byte[] b,int nStart,int nLen) IaO&f<^#o  
{ ~K(mt0T )  
int n = -1; BV}sN{  
try{ EDF0q i  
oSavedFile.write(b,nStart,nLen); .%M80X{5~  
n = nLen; dqFp"Xe"%  
} .CW,Td3f!  
catch(IOException e) _E/  
{ "2 :zWh7|  
e.printStackTrace (); @V^5_K  
} 2a 7"~z~  
b+$wx~PLi  
;r.#|b  
return n; 0eK>QZ_  
} oc[z dIk  
{)Shc;Qh  
 um2}XI  
} Wq}W )E  
nmyDGuzk  
>Y|P+Z\7  
/* by,3A  
**SiteInfoBean.java ~|LAe-e"  
*/ Eb5BJ-XeS^  
package NetFox; l=#b7rBP  
/2tP d  
J?hs\nA  
public class SiteInfoBean { -q&,7'V  
,F "P/`i'  
Wo,93]  
private String sSiteURL; //Site's URL 0;4 YU%u  
private String sFilePath; //Saved File's Path TnQW ~_:  
private String sFileName; //Saved File's Name l701$>>  
private int nSplitter; //Count of Splited Downloading File w")m]LV  
? Y luX  
80Q%c(i  
public SiteInfoBean() K=pG,[ChA  
{//nSplitter的缺省值为5 '#Do( U'  
//default value of nSplitter is 5 @,LU!#y(  
this("","","",5); I\IDt~  
} FiXqypT_(  
F4ylD5Y!  
x<.(fRv   
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^}J,;Zhu5  
{ )d|s$l$?7  
sSiteURL= sURL; #6pJw?[  
sFilePath = sPath; ,)VAKrSg  
sFileName = sName; h*3{IHAQ  
this.nSplitter = nSpiltter; G+I->n-s4  
!:}m-iqQ1  
Deq@T {  
} %:OX^ ^i;  
nE bZ8M  
TJZ arNc$  
public String getSSiteURL() Zt9ld=T  
{ 8m[o*E.4F  
return sSiteURL; ]]y,FQ,r  
} Zvra >%  
u EERNo&  
bHXoZix  
public void setSSiteURL(String value) ^SM5oK  
{ {Eqx'j  
sSiteURL = value; r-Y7wM`TZ  
} u_FN'p=.  
{]dvzoE]  
"EE (O9q  
public String getSFilePath() t oM+Bd:Y  
{ [lu+"V,<LJ  
return sFilePath; X}ihYM3y/  
} U_Q;WPJ  
uh>"TeOi  
- Nt8'-  
public void setSFilePath(String value) D<WGau2H  
{ {CFy %  
sFilePath = value; ]K%d   
} 7`^=Ie%(K  
KUU ZN  
0sCWIGU W  
public String getSFileName() }j!C+i  
{ /)?qD  
return sFileName; ?D(aky#cyc  
} 5'<a,,RKu  
voJJoy%  
7I;0 %sVQ{  
public void setSFileName(String value) O[p c$Pi  
{ BA8!NR|  
sFileName = value; =F5zU5`i  
} Tr;&bX5]H  
7;Vmbt9  
'?LqVzZI  
public int getNSplitter() -<e_^  
{ IOJLJ p  
return nSplitter; =?N$0F!  
} 6}Rb-\N  
}%^3  
c6iFha;db  
public void setNSplitter(int nCount) ^g.H JQ'vF  
{ [@]i_L[  
nSplitter = nCount; Os!x<r|r  
} 1@F>E;YjL=  
} X?(R!=a  
"I@akM$x  
F;Q'R |HQ  
/* u(PUbxJ V  
**Utility.java xlh<}V tp  
*/ kjt(OFh'Y+  
package NetFox; l%qh^0  
by$mD_sr  
~D`  
public class Utility { U99Uny9  
=c%gV]>G  
#RKd >ig%  
public Utility() _<l)4A3rS  
{ LCe6](Z  
57_AJT hR  
Iv u'0vF  
} Wq?vAnLbk  
<oSx'_dc  
//线程睡眠 Jyp7+M]  
public static void sleep(int nSecond) p[;@9!t  
{ 8~O0P=  
try{ B3I0H6O  
Thread.sleep(nSecond); >LB*5  
} z$Qy<_l  
catch(Exception e) \3hFb,/4k  
{ tJm1Q#||  
e.printStackTrace (); ;qcOcm%  
} gf^y3F[\  
} c(!pcB8  
6QNZ/Ox:  
//日志 _T;Kn'Gz(&  
public static void log(String sMsg) Zm+GH^f'  
{ 98vn"=3  
System.err.println(sMsg); o)'06FF\$  
} D4?cnwU  
JM53sx4&  
<L2z|%`  
public static void log(int sMsg) H8m[:K]_H  
{ R{6M(!x  
System.err.println(sMsg); } V"A;5j`  
} WE+Szg(4x  
} /4upw`35]  
c@KNyBy2  
>GmO8dK  
/* &4*f28 s  
**TestMethod.java <y#@v  G  
*/ `9A`pC  
package NetFox; J6@RIia  
rmdg~  
fVi[mH0=+  
public class TestMethod { 48{B}j%oU  
X9C:AGbp  
y!|4]/G]?t  
public TestMethod() +=*ND<$n/E  
{ ///xx/weblogic60b2_win.exe //bQD>NBO  
try{ Fw^^sB  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b27t-p8  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Rhw+~gd*F  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7 4hRG~  
fileFetch.start(); 6t'.4SR  
} -67!u;  
catch(Exception e){e.printStackTrace ();} G}aM~,v  
X<f4X"y  
Ty*+?#`  
} n} ]gAX  
t$lJgj(  
3(:?Z-iKe  
public static void main(String[] args) g+xcKfN{  
{ {J/+KK  
new TestMethod(); 7'ws: #pC  
} 7UUu1"|a|  
} \vuWypo  
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