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http断点续传简单实现(java)

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/* d^h`gu~3  
**SiteFileFetch.java m'HAt~  
*/ 5 XtIVHA@{  
package NetFox; fSc)PqLP  
import java.io.*; t@r>GHO  
import java.net.*; ~(aMKB  
~i_YrTp  
@%iZT4`Ejf  
public class SiteFileFetch extends Thread { 69< <pm,m  
pY.R?\  
Kcl~cIh77  
SiteInfoBean siteInfoBean = null; //文件信息Bean o0ky]9 P  
long[] nStartPos; //开始位置 5?l8;xe`{f  
long[] nEndPos; //结束位置 x Zp`  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 gi {rqM  
long nFileLength; //文件长度 %vn"tp  
boolean bFirst = true; //是否第一次取文件 HE!"3S2S&+  
boolean bStop = false; //停止标志 0MpZdJ  
File tmpFile; //文件下载的临时信息 Z;/QB6|%  
DataOutputStream output; //输出到文件的输出流 Y]!WPJ`f2  
zD^*->`p  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Aq 5CF`e{  
public SiteFileFetch(SiteInfoBean bean) throws IOException R ?62g H  
{ {:;6 *W  
siteInfoBean = bean; OTe h8h  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); <cm(QNdcC  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Dxvizd>VU  
if(tmpFile.exists ()) 1FA:"0lO  
{ KpX1GrIn3  
bFirst = false; s#cb wDT  
read_nPos(); ==#mlpi`S[  
} ^O6eFD U  
else G]v BI=  
{ UpTVLx^c  
nStartPos = new long[bean.getNSplitter()]; mY= Q#nG  
nEndPos = new long[bean.getNSplitter()]; c,j[ix  
} '8w}m8{y  
{<cL@W  
B)/L[ )S  
@bRKJPU9)  
} e@h (Zwp  
h-.xx 4D  
 ^t}1 $H  
public void run() 9QP-~V{$  
{ :_8Nf1B+T  
//获得文件长度 ~`97?6*Ra  
//分割文件 -kk0zg &|i  
//实例FileSplitterFetch Talmc|h  
//启动FileSplitterFetch线程 "LNLM  
//等待子线程返回 =O%Hf bx  
try{ G!)Q"+  
if(bFirst) ;~,)6UX7  
{ N?EeT}m_  
nFileLength = getFileSize(); utu V'5GD  
if(nFileLength == -1) gWD46+A){  
{ kk>z,A4 h_  
System.err.println("File Length is not known!"); Ev Ye1Y-  
} CL3b+r  
else if(nFileLength == -2) $;pHv<  
{ z[Ah9tM%  
System.err.println("File is not access!"); 8-B6D~i  
} Y(RB@+67  
else &>f]  
{ %63s(ekU  
for(int i=0;i<nStartPos.length;i++) [a_'pAH  
{ 5[y+X|Am  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 8,@0~2fz#  
} u|"y&>!R-  
for(int i=0;i<nEndPos.length-1;i++) lFtH;h,==v  
{ dI+Y1Vq  
nEndPos = nStartPos[i+1]; _]v@Dq VP  
} x,NV{uG$n  
nEndPos[nEndPos.length-1] = nFileLength; 4 _P6P  
}  "F=ta  
} 6]r#6c %  
!o`riQLs>  
r]0>A&,  
//启动子线程 vRh)o1u)  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ) 7C+hQe  
for(int i=0;i<nStartPos.length;i++) W m&*  
{ 0`/CoP<U  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q{|_"sfJ  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `mthzc3W  
nStartPos,nEndPos,i); wQ^RXbJI9  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oFb~|>d  
fileSplitterFetch.start(); .~C%:bDnX7  
} EK&";(x2(  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a>Wr2gPko  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *X5<]{7c  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <0!<T+JQ  
nEndPos = " + nFileLength); ;i?rd f  
// fileSplitterFetch[nPos.length-1].start(); G<-<>)zO!  
Hqtv`3g  
)(9[>_+40  
//等待子线程结束 ^z`d 2it  
//int count = 0; 3bRW]mP8  
//是否结束while循环 fg7  
boolean breakWhile = false; 7|xu)zYB  
WMa`! Q  
Y P,>vzW  
while(!bStop) ?AO22N|j  
{ K$l@0r ~k  
write_nPos(); j}O qWX>/  
Utility.sleep(500); ]N2! 'c  
breakWhile = true; D*>#]0X  
QHxof7  
;F_P<b 2  
for(int i=0;i<nStartPos.length;i++) \.'[!GE*c  
{ 1Va=.#<  
if(!fileSplitterFetch.bDownOver) F9"Xu-g  
{ Z~w2m6;s  
breakWhile = false; O!t=,F1j  
break; Ih N^*P:Fo  
} LzxO=+=9!q  
} zGdYk-H3TH  
if(breakWhile) /'/i?9:  
break; 4jc?9(y%  
vjzG H*  
5Bt~tt  
//count++; $<9u:.9xf  
//if(count>4) AhkDLm+  
// siteStop(); b!e0pFS;  
} LJ6l3)tpD  
zwU1(?]I{  
t,n2N13  
System.err.println("文件下载结束!"); W~PMR/^i  
} Yw yMC d  
catch(Exception e){e.printStackTrace ();} rog1  
} l3*GQ~m7  
q65]bs4M  
$Dd-2p   
//获得文件长度 -&Q+x,.%  
public long getFileSize() artn _  
{ dz^b(q  
int nFileLength = -1; P,xIDj4d  
try{ ^?wR{q"8  
URL url = new URL(siteInfoBean.getSSiteURL()); M.xZU\'ty  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D2GF4%|  
httpConnection.setRequestProperty("User-Agent","NetFox"); }'?qUy3x  
8A5/jqnqt  
SdN&%(ZE  
int responseCode=httpConnection.getResponseCode(); EDuH+/:n  
if(responseCode>=400) @q`T#vd  
{ 5dhy80|g]  
processErrorCode(responseCode); oaZdvu@y  
return -2; //-2 represent access is error C_'EO<w$  
} E[7E%^:Mg  
 q(X7e  
WNZYs  
String sHeader; ( et W4p  
6O,:I  
in5e *  
for(int i=1;;i++) l p(D@FT  
{ -Lq2K3JHyn  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V1,/qd_  
//Utility.log(in.readLine()); g*(z .  
sHeader=httpConnection.getHeaderFieldKey(i); LuHRB}W  
if(sHeader!=null) ;aj;(Z.p)  
{ Alo L+eN@  
if(sHeader.equals("Content-Length")) pF7N = mO  
{ <f`n[QD2z  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }#-@5["-X  
break; `N&*+!O%  
} ^{{a v?h  
} q)f_!N  
else Bz <I7h  
break; )0/*j]Kf  
} nF_q{e7  
} AorY#oq  
catch(IOException e){e.printStackTrace ();} L N Fe7<y  
catch(Exception e){e.printStackTrace ();} j"'a5;Sy  
a5R. \a<q  
M PDRMGR@i  
Utility.log(nFileLength); <R+?>kz6  
l S3LX  
L"/ ?[B":  
return nFileLength; )bR0 >3/  
} BWvM~no  
x.Egl4b3  
%)r:!R~R  
//保存下载信息(文件指针位置) J <;xkT1x  
private void write_nPos() iCA-X\E  
{ lVQE}gd%m  
try{ (9oo8&GG  
output = new DataOutputStream(new FileOutputStream(tmpFile)); j7MUA#6$  
output.writeInt(nStartPos.length); !tt 8-Y)i  
for(int i=0;i<nStartPos.length;i++) hRRxOr#*$  
{ H la?\  
// output.writeLong(nPos); u z7|!G!43  
output.writeLong(fileSplitterFetch.nStartPos); C0 KFN  
output.writeLong(fileSplitterFetch.nEndPos); 7Mq{Py1  
} Il9xNVos#  
output.close(); Y,GlAr s4  
} CQNMCYjg(R  
catch(IOException e){e.printStackTrace ();} <tBT?#C9+  
catch(Exception e){e.printStackTrace ();} 9 " t;6  
} z@,(^~C_  
Z$g'h1,zW  
vanV|O  
//读取保存的下载信息(文件指针位置) [5p3:D  
private void read_nPos() l"(PP3  
{ 5I,NvHD4  
try{ yf0v,]v[  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pi~5}bF!a  
int nCount = input.readInt(); as]M%|/-I  
nStartPos = new long[nCount]; Im\ ~x~{  
nEndPos = new long[nCount]; z,$uIv}'@  
for(int i=0;i<nStartPos.length;i++) S6(48/  
{  @--"u_[  
nStartPos = input.readLong(); |'1.a jxw  
nEndPos = input.readLong(); Jz>P[LcB  
} Za1mI^ L1  
input.close(); [ i, [^  
} E"_{S.Wc  
catch(IOException e){e.printStackTrace ();} 1HKA`]D"p  
catch(Exception e){e.printStackTrace ();} 0?8>{!I  
} _hyqHvP  
-&`_bf%M  
E b:iym0  
private void processErrorCode(int nErrorCode) i+mU(/l2{  
{ K<:%ofB"S  
System.err.println("Error Code : " + nErrorCode); c5$DHT @N"  
} (J%4}Dm  
] 1pIIX}  
V\x'w*FP  
//停止文件下载 2,q*8=?{6P  
public void siteStop() ?k4Hk$V  
{ dp^PiyL  
bStop = true; gJr)z7W'8  
for(int i=0;i<nStartPos.length;i++) )W 5g-@  
fileSplitterFetch.splitterStop(); t`E5bWG  
]o]`X$n  
JyTETf,y  
} Ewp2 1  
} B G\)B  
//负责部分文件的抓取 )K@D4sl  
**FileSplitterFetch.java e-P{)L<s5  
*/ H[p~1%Lq  
package NetFox; A r~/KRK  
-rI7ihr*  
S$hxR  
import java.io.*; e|~{ X\l  
import java.net.*; y>0 @.  
"lu^  
Bo8f52|  
public class FileSplitterFetch extends Thread { Z(tJd ,  
:*,!gf  
D((/fT)eD  
String sURL; //File URL )s^gT]"N  
long nStartPos; //File Snippet Start Position nVWU\$Ft  
long nEndPos; //File Snippet End Position eA2*}"W  
int nThreadID; //Thread's ID 0J'Cx&Rg  
boolean bDownOver = false; //Downing is over Zf}2c8Vc4  
boolean bStop = false; //Stop identical W|@SXO)DY  
FileAccessI fileAccessI = null; //File Access interface 72xf| s=  
g]HWaFjc5  
T88$sD.2 '  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4 qsct@K,  
{ r9u'+$vmF  
this.sURL = sURL; q`{@@[/ (y  
this.nStartPos = nStart; w9GY/]  
this.nEndPos = nEnd; 75^*4[  
nThreadID = id; Gdb0e]Vt+  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5)S;R,  
} A\rY~$Vr  
#aC&!Rei{  
iUh7eR9  
public void run() D9NRM;v  
{  +qj Z;5(  
while(nStartPos < nEndPos && !bStop) *!"T^4DEg  
{ > `eo0  
ufR>*)_+  
ag:<%\2c  
try{ O}cfb4"  
URL url = new URL(sURL); _){u5%vv  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |tI{MztJ"c  
httpConnection.setRequestProperty("User-Agent","NetFox"); B&X)bGx8  
String sProperty = "bytes="+nStartPos+"-"; J+ :3== ,  
httpConnection.setRequestProperty("RANGE",sProperty); 6Zw$F3 <  
Utility.log(sProperty); u;^H=7R  
[= E=H*j  
vFJ4`Gjw(  
InputStream input = httpConnection.getInputStream(); HI D6h!  
//logResponseHead(httpConnection); UV;I6]$}A7  
l2Py2ZI-b  
b_{+OqI  
byte[] b = new byte[1024]; ` k I}p  
int nRead; KS~Q[-F1P  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &f'Lll  
{ hOLlZP+  
nStartPos += fileAccessI.write(b,0,nRead); Om:Gun\%  
//if(nThreadID == 1) 1iR\M4?Frf  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #Qz 9{1\G  
} K ~\b+  
qfFa" a  
EMH-[EBx  
Utility.log("Thread " + nThreadID + " is over!"); EiM\`"o  
bDownOver = true; ~8k`~t!  
//nPos = fileAccessI.write (b,0,nRead); ]A-LgDsS  
} jK6dI 7h  
catch(Exception e){e.printStackTrace ();} |Zn,|-iW  
} %iIr %P?  
} kH0kf-4\  
lp$,`Uz`  
j/uMSE  
//打印回应的头信息 epk C '  
public void logResponseHead(HttpURLConnection con) 8[^b8^  
{ E]a,2{&8<  
for(int i=1;;i++) l3MA&&++KF  
{ 2g)q (  
String header=con.getHeaderFieldKey(i); 8j&1qJx)  
if(header!=null) U .^%7.  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q"pZPpl&  
Utility.log(header+" : "+con.getHeaderField(header)); -y&>&D  
else u^ wG Vg  
break; 4yxf/X)  
} !&KE">3Qu  
} 65 &+Fv  
}VH` \g}  
= "Lb5!  
public void splitterStop() Jn?ZJZ  
{ P6^\*xkMr  
bStop = true; ='eQh\T)  
} 9J49s1  
2+(SR.oGq  
fEK%)Z:0  
} )J\ JAUj  
$Ovq}Rexc  
:Z;kMrU  
/* "NSY=)fV  
**FileAccess.java p_g8d&]V  
*//文件访问(定位,写) P)=$0kR3  
package NetFox; =snJ+yn!  
import java.io.*; bb/A}< zD  
m:;`mBOc3  
#{bT=:3a  
public class FileAccessI implements Serializable{ 4%jSqT@  
v>Kv!OY:c  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ir )~T0  
RandomAccessFile oSavedFile; Vc|QW  
long nPos; Mm"0Ip2"  
[ dVRVm0N  
m<4tH5 };d  
public FileAccessI() throws IOException W6 *5e{  
{ kf",/?s2Z  
this("",0); H8qAj  
} 3AuLRI  
L{6Vi&I84[  
$>l65)(E\  
public FileAccessI(String sName,long nPos) throws IOException <M3&\  
{ NydoX9  
oSavedFile = new RandomAccessFile(sName,"rw"); gAGcbepX  
this.nPos = nPos; <^A1.o< GN  
oSavedFile.seek(nPos); 9@p+g`o  
} g7LS  
7tT L,Nxe  
wAF#N1-k  
public synchronized int write(byte[] b,int nStart,int nLen) VelX+|w  
{ l) )Cvre+  
int n = -1; R^4 j0L  
try{ @JD!.3  
oSavedFile.write(b,nStart,nLen); 7bam`)n  
n = nLen; %Zu+=I Z  
} o:/yme G  
catch(IOException e) 8bEii1EM  
{ { r8H5X  
e.printStackTrace (); oJ}$ /_  
} /u'M7R  
b;(BMO,(  
O#D N3yu?  
return n; {D8[pG%z  
} pB]+c%\  
-+|{#cz  
]M9r<x*  
} ZEU/6.  
^5gB?V,  
|f&=9%  
/* &uTK@ G+  
**SiteInfoBean.java 7;:Uv=  
*/ o>4GtvA*  
package NetFox; ?pF uV`Zm  
<NX6m|DD  
M$GZK'%  
public class SiteInfoBean { Jp`qE  
ulnlRx  
P EAo'63$  
private String sSiteURL; //Site's URL T .L>PL ?=  
private String sFilePath; //Saved File's Path )eSD5hOI)  
private String sFileName; //Saved File's Name 1:iT#~n  
private int nSplitter; //Count of Splited Downloading File ?`D/#P  
XFN4m #  
V\o& {7!  
public SiteInfoBean() 0j|JyS:}G  
{//nSplitter的缺省值为5 @460r  
//default value of nSplitter is 5 PP)-g0^@  
this("","","",5); W[tX%B  
} ::rKW *?  
!@-g9z  
KF`@o@,  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zz+[]G+"2m  
{ )y}W=Q>T  
sSiteURL= sURL; 4~/3MG  
sFilePath = sPath; T]Eg9Y:+v  
sFileName = sName; Tj*Vk $}0  
this.nSplitter = nSpiltter; t1tZ:4  
o@0p  
8L*P!j9`EY  
} CR<Nau>  
_!*??B6u  
n$y)F} .-  
public String getSSiteURL() 4!KUPgg  
{ OmX(3>:9  
return sSiteURL; ?KfV>.()  
} u CNi&.  
5}t}Wc8  
(>\w8]  
public void setSSiteURL(String value) ww"HV;i  
{ -F|C6m!  
sSiteURL = value; 6>Szxkz  
} >A;9Ee"&  
]RJcY1  
5 J9,/M0  
public String getSFilePath() )9 QeVf  
{ k9<P]%  
return sFilePath; ]2P*Z6Az  
} L.@o  
.-g++f(_i  
#{kwl|c   
public void setSFilePath(String value) \{ui{8+G  
{ nZ 0rxx[V?  
sFilePath = value; U&\8~h  
} jQiK of>  
do1aH$Iw  
2= 6}! Y  
public String getSFileName() IA XoEBlMs  
{ 80M"`6  
return sFileName; eD4o8[s  
} *h>KeIB;  
]D;X"2I2'b  
ED={OZD8  
public void setSFileName(String value) C&vUZa[p  
{ MZX-<p+  
sFileName = value; }G#TYF}  
} 3i'L5f67  
Xn'{g  
26,!HmtC  
public int getNSplitter() CcZ\QOet&C  
{ lklMdsIdj  
return nSplitter; M 8BN'% S  
} Ok=RhoZZ  
iwl\&uNQU  
[y}0X^9,E  
public void setNSplitter(int nCount) ;r_YEPlZ  
{ 2 R !1Vl  
nSplitter = nCount; RTW4r9~'  
} =;9*gDfD  
} /{';\?w  
2,Og(_0>  
f@%H"8w!  
/* m|)Mc VV  
**Utility.java C[ ehw  
*/ I'h6!N"  
package NetFox; 0P<bS?e<l  
jcWv&u|  
w{t2Oo6Q0+  
public class Utility { _BV'J92.  
9oK#n'hjb  
=!b<@41  
public Utility() G02(dj  
{ 1{8SKfMdP  
PyD'lsV  
vPn(~d_  
} *.UM[Wo  
6p X[m{  
//线程睡眠 Jbud_.h9  
public static void sleep(int nSecond) $Q[a^V~:  
{ ^;b$`*M1  
try{ YI=03}I  
Thread.sleep(nSecond); %8)GuxG*  
} tTT./-*0  
catch(Exception e) )pS1yYLj  
{ 4|ryt4B  
e.printStackTrace (); aD aQ 7i  
} 0B^0,d(s  
} CF`tNA3fxm  
ik@g;>pQD  
//日志 S(^*DV  
public static void log(String sMsg) ]OE{qXr{  
{ 0jsU^m<g  
System.err.println(sMsg); 9OeY59 :  
} :h1-i  
0Dj<-n{9  
;IC:]Zu  
public static void log(int sMsg) HB+\2jEE  
{ +)C?v&N  
System.err.println(sMsg); QfuKpcT &  
} 5G@z l  
} p!MOp-;-  
P#/k5]g  
#<X+)B6t  
/* U5; D'G  
**TestMethod.java OTA@4~{C  
*/ FnN@W^/z  
package NetFox; 85rXm*Df  
qNP&f 8fH  
&D "$N"  
public class TestMethod { N 4$!V}pp  
v,N*vqWS  
 7(;M  
public TestMethod() _L mDF8Q(  
{ ///xx/weblogic60b2_win.exe X6jW mo8]  
try{ }yup`R  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y%v?ROql  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =@U~ sl [  
SiteFileFetch fileFetch = new SiteFileFetch(bean); b{|Ha3;w  
fileFetch.start(); Yyq:5V!  
} NPws^  
catch(Exception e){e.printStackTrace ();} -hav/7g  
Y_3 {\g|x  
uFDJRQJ<  
} %oas IiO  
'u }|~u?m  
SomA`y+ERn  
public static void main(String[] args) F V8K_xj  
{ M),i4a?2  
new TestMethod(); wu5]S)?*  
} Pa%;[hbn  
} */iD68r|-  
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