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http断点续传简单实现(java)

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/* ]u"x=S93  
**SiteFileFetch.java =_`cY^ib+  
*/ 8lF:70wia  
package NetFox; ^\3z$ntF  
import java.io.*; 5>rjL ;  
import java.net.*; 'UB"z{w%  
[<VyH.  
W! GUA<  
public class SiteFileFetch extends Thread { Fj1'z5$  
R3E|seR  
10r9sR  
SiteInfoBean siteInfoBean = null; //文件信息Bean $H1igYc  
long[] nStartPos; //开始位置 A "~Oi  
long[] nEndPos; //结束位置 BV]$= e'  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 wQ\bGBks  
long nFileLength; //文件长度 =[`gfw  
boolean bFirst = true; //是否第一次取文件 ;>jOB>b{h  
boolean bStop = false; //停止标志 XF99h&;9  
File tmpFile; //文件下载的临时信息 UsdUMt!u  
DataOutputStream output; //输出到文件的输出流 l"9$lF}  
y(jd$GM|  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) iU4Z9z!  
public SiteFileFetch(SiteInfoBean bean) throws IOException : W0;U  
{ '! ~ s=  
siteInfoBean = bean; ilFS9A3P  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); {EVHkQ+o  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); xd]7?L@h.I  
if(tmpFile.exists ()) _ Zzne  
{ ybpU?n  
bFirst = false; q ?m<9`  
read_nPos(); z A@w[.  
} dt(Lp_&v  
else #YB3Ug]z  
{ )!d_Td\-  
nStartPos = new long[bean.getNSplitter()]; hr/|Fn+kA  
nEndPos = new long[bean.getNSplitter()]; OCI{)r<O2m  
} > `+lEob  
qEnmms1  
NucLf6  
. "`f~s\G  
} OZE.T-{  
E# *`u  
dlc'=M  
public void run() ex)U'.^  
{ B[[1=  
//获得文件长度 !tuK.?q|l  
//分割文件 vXibg  
//实例FileSplitterFetch wKAxUPzm  
//启动FileSplitterFetch线程 qX*Xo[Xp  
//等待子线程返回 ;Dc\[r  
try{ o^<W3Z  
if(bFirst)  fG|+ !  
{  Rlx  
nFileLength = getFileSize(); KL8WT6!RZ  
if(nFileLength == -1) YtY.,H;  
{ W29GM -,K  
System.err.println("File Length is not known!"); @D@'S:3  
} 2w /qH4  
else if(nFileLength == -2) c/`Rv{ *'o  
{ :c0 |w  
System.err.println("File is not access!"); Kg#s<#h  
} *jo1?  
else [3io6XG x@  
{ V-z F'KI[  
for(int i=0;i<nStartPos.length;i++) :*)b<:4  
{ k1;Jkq~  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); [N1[khY`  
} UQCond+K  
for(int i=0;i<nEndPos.length-1;i++) *AA78G|  
{ fDZnC Fa  
nEndPos = nStartPos[i+1]; fh@/fd  
} u&$1XZ!es  
nEndPos[nEndPos.length-1] = nFileLength; B \>W  
} ^j]"5@f  
} `-<m#HF:)d  
Bt"*a=t;  
30L/-+r1  
//启动子线程 |sV@j_TX  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; juBzpQYj  
for(int i=0;i<nStartPos.length;i++) vz'<i. Yv4  
{ L'}^Av_+  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mW @Z1Plxs  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rcG-V f@  
nStartPos,nEndPos,i); vmT6^G  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e}q!m(K]e-  
fileSplitterFetch.start(); Zz56=ZX*_  
} 0p!N'7N  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `;#I_R_K  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kl9<l*  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1Yy*G-7}  
nEndPos = " + nFileLength); dF0:'y  
// fileSplitterFetch[nPos.length-1].start(); Kw,ln<)2  
}#9 |au`  
`pYL/[5  
//等待子线程结束 3Tr}t.mt  
//int count = 0; ,:"c"   
//是否结束while循环 KPs @v@5M  
boolean breakWhile = false; )\,hc$<=m  
d,%@*v]S  
KS(Ms*k;'  
while(!bStop) O<6!?1|KP  
{ v@ OM  
write_nPos(); X>VxE/  
Utility.sleep(500); (1?k_!)T  
breakWhile = true; ?[S{kMb2  
s h^&3}  
-xc'P,`  
for(int i=0;i<nStartPos.length;i++) "Yf?33UNZ  
{ nv"D  
if(!fileSplitterFetch.bDownOver) ?c# v'c^=h  
{ 4p_@f^v~QH  
breakWhile = false; HH,G3~EBF  
break; p4I6oS`/.  
} ~CL^%\K  
} ;gv9J [R  
if(breakWhile) t&Z:G<;  
break; qf6}\0   
SZ"^>}zl=  
Gzu $  
//count++; KoO\<_@";  
//if(count>4) 3?oj46gP  
// siteStop(); XW9 [VUW~  
} y5 bELWA  
RBM4_L  
Bc2PF;n  
System.err.println("文件下载结束!"); *`.4M)Ym~  
} LjA>H>8%[  
catch(Exception e){e.printStackTrace ();} h;sdm/  
} 7q,M2v;  
~`x<;Ts  
t= oTU,<  
//获得文件长度 gEQevy`T%c  
public long getFileSize() Cn(0ID+3f  
{ @ 6{U*vs  
int nFileLength = -1; 80qe5WC.2u  
try{ kVb8$Sp  
URL url = new URL(siteInfoBean.getSSiteURL()); 4>xv7  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WgQ6EV`  
httpConnection.setRequestProperty("User-Agent","NetFox"); -QUvd1S40  
UHW;e}O5  
eA(c{  
int responseCode=httpConnection.getResponseCode(); J#'+&D H  
if(responseCode>=400) 4`+hX'  
{ Oy/+uw^  
processErrorCode(responseCode); {,rVA(I@  
return -2; //-2 represent access is error Nm]\0m0p-  
} fr<, LC.  
9K F`9Y  
$di8#O*  
String sHeader; S\O6B1<:  
O<v9i4*  
SRx `m,535  
for(int i=1;;i++) *S@0o6v  
{ mf)o1O&B  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (j;6}@  
//Utility.log(in.readLine()); "|l-NUe  
sHeader=httpConnection.getHeaderFieldKey(i); ,:QDl  
if(sHeader!=null) BnLWC  
{ N2^B  
if(sHeader.equals("Content-Length")) saaN$tU7  
{ 0jN?5j  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K q0!.455  
break; c 0%%X!!$  
} W!BIz&SY:-  
} JH0L^p   
else W}U-u{Z  
break; 9 6'{ES9D  
} V+kU^mI  
} /n SmGAO  
catch(IOException e){e.printStackTrace ();} :9`T.V<?  
catch(Exception e){e.printStackTrace ();} *!*J5/ b  
cSSrMYX2  
Z{ A)  
Utility.log(nFileLength); *OQr:e<}  
G:2m)0bW  
;9hi2_luV  
return nFileLength; -v(.]`Wo&;  
} &<E*W*b[  
w&7-:."1i  
8f<[Bu ze  
//保存下载信息(文件指针位置) uE6;;Ir#mF  
private void write_nPos() Gq/f|43}@O  
{ @ 0RB.-  
try{ zU9G: jH  
output = new DataOutputStream(new FileOutputStream(tmpFile)); kG7q4jFwP  
output.writeInt(nStartPos.length); Z) zWfv}  
for(int i=0;i<nStartPos.length;i++) ~agzp`!M  
{ ^{T3lQvt  
// output.writeLong(nPos); )c#m<_^  
output.writeLong(fileSplitterFetch.nStartPos); ]jz%])SzH  
output.writeLong(fileSplitterFetch.nEndPos); Ppzd.=E  
} +89s+4Jn  
output.close(); bt,^-gt@  
} &ns !\!  
catch(IOException e){e.printStackTrace ();} 89@e &h*  
catch(Exception e){e.printStackTrace ();} {g>k-.  
} })R8VJ&C/  
YolO-5  
-m:i~^ u  
//读取保存的下载信息(文件指针位置) d4#Q<!r  
private void read_nPos() I9`R L Sn  
{ Oop;Y^gG}  
try{ KGclo-,  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Uk02VuS  
int nCount = input.readInt(); jy] hP?QG  
nStartPos = new long[nCount]; Dm j^aFB0|  
nEndPos = new long[nCount]; F-)lRGw  
for(int i=0;i<nStartPos.length;i++) < }3c%Q1  
{ %7PprN0>  
nStartPos = input.readLong(); 6.Nu[-?  
nEndPos = input.readLong(); >a;^=5E  
}  h7-!q@  
input.close(); .oq!Ys4KA  
} bqXCe\#  
catch(IOException e){e.printStackTrace ();} AFWcTz6#d  
catch(Exception e){e.printStackTrace ();} Hb3+$vJ^  
} Q)c $^YsI  
e'oM% G[  
:4"SJ  
private void processErrorCode(int nErrorCode) +b.qzgH>r  
{ VJX{2$L  
System.err.println("Error Code : " + nErrorCode); XB)e;R  
} gOI #$-L  
`MgR/@%hr  
`CI9~h@k  
//停止文件下载 \guZc}V]:\  
public void siteStop() .[hQ#3)W  
{ %:n1S]Vr  
bStop = true; mN^92@eebC  
for(int i=0;i<nStartPos.length;i++) {6v|d{V+e  
fileSplitterFetch.splitterStop(); /vl]Oa&U  
!<!sB)  
kSH3)CC P  
} b'^OW  
} xQ62V11R6  
//负责部分文件的抓取 8{HeHU  
**FileSplitterFetch.java /LM*nN$%  
*/ "3{xa;c  
package NetFox; ~pn9x;N%H  
6y,M+{  
:z%vNKy1  
import java.io.*; &+-ZXN  
import java.net.*; S<f&?\wK=v  
w~EXO;L2  
J'4{+Q_pa  
public class FileSplitterFetch extends Thread { }(AUe5aw`G  
>wjWX{&?  
aTs5^Kh')  
String sURL; //File URL f- pt8  
long nStartPos; //File Snippet Start Position V#1_jxP)Q  
long nEndPos; //File Snippet End Position X-! yi  
int nThreadID; //Thread's ID ~1pJQ)!zlq  
boolean bDownOver = false; //Downing is over @5H1Ni5/o@  
boolean bStop = false; //Stop identical o$m64l  
FileAccessI fileAccessI = null; //File Access interface br}.s@~  
36JVnW;  
BbZ-dXC<  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D>,]EE-  
{ ^>uzMR!q5  
this.sURL = sURL; sJX/YGHt  
this.nStartPos = nStart; h:(Jes2  
this.nEndPos = nEnd; -gh',)R   
nThreadID = id; l!\C"f1o,  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %*<k5#Yq  
} <pGPuw|~I  
g# :|Mjgh  
{a9Z<P  
public void run() ??{(.`}R~  
{ -8qLshQ  
while(nStartPos < nEndPos && !bStop) 9Ps:]Kp!vN  
{ ]DdD FLM  
MC/$:PV  
sMli!u  
try{ #$%9XD3  
URL url = new URL(sURL); .9> e r  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YL&$cT]1  
httpConnection.setRequestProperty("User-Agent","NetFox"); it\{#rb=4  
String sProperty = "bytes="+nStartPos+"-"; a=k+:=%y  
httpConnection.setRequestProperty("RANGE",sProperty); XZuJ<]}X,  
Utility.log(sProperty); a=gTGG"9  
&Z5$ 5,[  
0G9@A8LU  
InputStream input = httpConnection.getInputStream(); Giz9jzF \  
//logResponseHead(httpConnection); *#Hi W)  
]c+qD,wqt>  
<"/Y`/  
byte[] b = new byte[1024]; E8=.TM]L  
int nRead; %p"x|e  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '/SMqmi  
{ SxC$EQ gL  
nStartPos += fileAccessI.write(b,0,nRead); $I-$X?  
//if(nThreadID == 1) ExI?UGT  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3j0/&ON  
} JGf6*D"O  
8nQlmWpJ  
a9"x_IVU  
Utility.log("Thread " + nThreadID + " is over!");  OnF +  
bDownOver = true; @\Sa)  
//nPos = fileAccessI.write (b,0,nRead); J$&!Y[0  
} ]1%H.pF  
catch(Exception e){e.printStackTrace ();} }f^r@3Cb3  
} eGvHU ;@  
} 9#/z [!  
<!K2xb-d^  
u~Q0V J~  
//打印回应的头信息 J'Yj_  
public void logResponseHead(HttpURLConnection con) tQ'E"u1  
{ G=!Y~qg  
for(int i=1;;i++) q NU\XO`H  
{ wsP3hE' ]  
String header=con.getHeaderFieldKey(i); 5bv(J  T  
if(header!=null) XYWGX;.=  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); V>@NkQ<|y  
Utility.log(header+" : "+con.getHeaderField(header)); aCX](sN  
else {{f%w$r(  
break; LcE!e%3  
} }@4m@_gR?  
} }0?642 =-  
+KDB^{  
I5F oh|)  
public void splitterStop() h(]O;a-  
{ i5|A\Wv"  
bStop = true; J^pL_  
} >AV-i$4eQ@  
xv's52x  
s}`ydwSg8  
} w@nN3U+  
;_of'  
waQNX7Xdn  
/* c _O| ?1  
**FileAccess.java QgEG%YqB  
*//文件访问(定位,写) bL!NT}y`  
package NetFox; f'aUo|^?  
import java.io.*; "2 ma]Ps  
 ,L\OhT  
%D\TLY  
public class FileAccessI implements Serializable{ /Y:_qsO1  
B y6:  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9HRYk13ae  
RandomAccessFile oSavedFile; WY?(C@>s  
long nPos; p{t2pfb  
Sq UoXNw  
'_g8fz 3  
public FileAccessI() throws IOException W&}R7a@:<~  
{ d'kQE_y2.  
this("",0); tu6c!o,@  
} z++*,2F  
%@G<B  
\UGs_5OT  
public FileAccessI(String sName,long nPos) throws IOException aIRCz=N  
{ * ?rw'  
oSavedFile = new RandomAccessFile(sName,"rw"); Xl2Fgg}#  
this.nPos = nPos; y{s?]hLk  
oSavedFile.seek(nPos); 1*[h$Z&H?  
} E4HG`_cWb  
u\ytiGO*  
! 0fpD'f!n  
public synchronized int write(byte[] b,int nStart,int nLen) cA`R~o"  
{ R5r )01  
int n = -1; >UE_FC*u  
try{ EW0H"YIC  
oSavedFile.write(b,nStart,nLen); _w Cp.[3?t  
n = nLen; @GBS-iT3  
} C "<l}  
catch(IOException e) }7g\1l\  
{ P@lExF*D1:  
e.printStackTrace (); `T{{wty  
} zr\I1v]?1#  
l\ts!p4f$  
hp%|n:.G  
return n; 4M6o+WV  
} dU3UCD+2y  
@mNf(&  
/.aZXC$]  
} +AtZltM i  
IW Lv$bPZ/  
"7JO~T+v  
/* S@z$,}Yc`<  
**SiteInfoBean.java d\3L.5]X  
*/ xQ* U9Wt;T  
package NetFox; )T(xQ2&r4  
R4_4FEo  
w-AF5%gX  
public class SiteInfoBean { m%+W{N4Wb  
0 4x[@f`  
?M;2H {KG:  
private String sSiteURL; //Site's URL ^p|MkB?uM  
private String sFilePath; //Saved File's Path FdKp@&O+1  
private String sFileName; //Saved File's Name @%O"P9;s  
private int nSplitter; //Count of Splited Downloading File `]FA} wC  
f:B+R  
.*r ?zDV  
public SiteInfoBean() 7F>5<Gv:-  
{//nSplitter的缺省值为5 }C}~)qaZv+  
//default value of nSplitter is 5 ,1Suq\ L  
this("","","",5); c;&m}ImLe.  
} X'TQtI  
O9r3^y\>I  
[j?n}D@L  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U!XC-RA3 _  
{ SWz+.W{KQ"  
sSiteURL= sURL; e/r41  
sFilePath = sPath; 6$4G&'J  
sFileName = sName; ^IjKT  
this.nSplitter = nSpiltter; fYuJf,I[f  
#y&3`Nz3  
j_L 'Ztu3  
} ?NGM<nK;7  
9Y&n$svB  
 fv5'Bl  
public String getSSiteURL()  w+=>b  
{ 54JZEc  
return sSiteURL; lV?rC z  
} z. VuY3  
YKJk)%;+w  
<dV|N$WV  
public void setSSiteURL(String value) VSx[{yn  
{ 1U;je,)  
sSiteURL = value; |[>`3p"&  
} o*_[3{FU  
^ W eE%"  
al F*L  
public String getSFilePath() GLB7h 9>  
{ 9jDV]!N4  
return sFilePath; +6B(LPxgP  
} \tye:!a?;@  
I?G m  
H~i+: X=I  
public void setSFilePath(String value) 8v8?D8\=|  
{ 5,:>.LRA  
sFilePath = value; YjdCCju  
} b*',(J94  
RgHPYf{  
]!d #2(  
public String getSFileName() 'VS!<  
{ =<YG0K  
return sFileName; beRpA;  
} .5p"o-:D  
f>s3Q\+  
!e?=I  
public void setSFileName(String value) "A~\$  
{ awB1ryrOF  
sFileName = value; 4'Z=T\:  
} .2q7X{4=  
b2aPo M=  
3!_y@sWx  
public int getNSplitter() elG<\[  
{ U; JZN  
return nSplitter;  \U(qv(T  
} F-R4S^eV  
ZN~:^,PO/  
"^fcXV9Wp  
public void setNSplitter(int nCount) H{VVxj  
{ .}&bE1  
nSplitter = nCount; dGt;t5An V  
} f>k]{W Y  
} G#t!{Q}8  
&#;vR 0O  
oTS*k: C'  
/* luACdC  
**Utility.java Obgn?TAVX  
*/ N\ChA]Ck  
package NetFox; a[Ah  
q(p]6Ha|  
H5'/i;  
public class Utility { 'h53:?~  
z|^:1ov,  
3,DUT{2  
public Utility() :aI[ lZ  
{ 1Jg&L~Ws"  
y2;uG2IS_g  
yDg`9q.ckm  
} eU&[^  
]dHU  
//线程睡眠 .t*MGUg  
public static void sleep(int nSecond) FloCR=^H  
{ qPDe;$J)  
try{ }enm#0Ha  
Thread.sleep(nSecond); PN:/lIO  
} H:Y?("k  
catch(Exception e) @W[`^jfQ  
{ f]W$4f {  
e.printStackTrace (); 62TWqQ!9d  
} 15U]/?jv8  
} ZX[ @P?A+-  
/Fy2ZYs,`8  
//日志 HR]*75}e  
public static void log(String sMsg) Yj)H!Cp.xD  
{ 0}}b\!]9  
System.err.println(sMsg); xTiC[<j  
} f40xS7-Q0  
R8O; 8c?D  
1vk& ;  
public static void log(int sMsg) i%w[v_j  
{ %MGbIMpY  
System.err.println(sMsg); 4WU%K`jnXb  
} J:LwO  
} mj:X'BVA  
04g=bJ  
i,|2F9YH  
/* `d]D=DtH  
**TestMethod.java BQ! v\1'C  
*/ P7np -I*  
package NetFox; x8 :  
bwN>E+  
8WU_d`DF  
public class TestMethod { V| 9<*  
uv,&/ ,;S  
TK^9!3  
public TestMethod() :'p+Ql~c  
{ ///xx/weblogic60b2_win.exe K,_d/(T4  
try{ ;|7]%Z}%  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P(AcDG6K  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |rW,:&;  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1~rZka[s  
fileFetch.start(); R@zl?>+  
} xNDX(_U>\  
catch(Exception e){e.printStackTrace ();} f/+UD-@%m  
OwRH :l  
o^HzE;L}  
} L-SWs8  
 {}x{OP  
~Y;_vU  
public static void main(String[] args) "A?&`}%  
{ Z ,4G'[d  
new TestMethod(); Q|T9 tc->  
} tA;#yM;  
} 4FLL*LCNX  
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