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http断点续传简单实现(java)

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/* K<L%@[gi  
**SiteFileFetch.java qM:)daS1w  
*/ ]>4Qs  
package NetFox; (Nlm4*{h  
import java.io.*; !zkEh9G  
import java.net.*; F+$@3[Q`N  
@[b:([  
ty< tv|p  
public class SiteFileFetch extends Thread { lPN< rgg  
T17LYHIT  
6-X?uaY)os  
SiteInfoBean siteInfoBean = null; //文件信息Bean hYZ:" x  
long[] nStartPos; //开始位置 Dw ;vDK  
long[] nEndPos; //结束位置 oplA'Jgnv  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 4p.{G%h  
long nFileLength; //文件长度 zT-"kK  
boolean bFirst = true; //是否第一次取文件 Okg8Ve2  
boolean bStop = false; //停止标志 Y 6Qb_X:  
File tmpFile; //文件下载的临时信息 , sJfMY  
DataOutputStream output; //输出到文件的输出流 Sw( H]  
Rw{v"n  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类)  ~M^7qO  
public SiteFileFetch(SiteInfoBean bean) throws IOException K y4y  
{ 'MQGR@*  
siteInfoBean = bean; GK+\-U)v  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); -Us% g  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); }~C ZqIP  
if(tmpFile.exists ()) x0;}b-f  
{ / bu<,o  
bFirst = false; lg  
read_nPos(); ^-;Z8M  
} }7 z+  
else $)7f%II  
{ '/*c Yv45  
nStartPos = new long[bean.getNSplitter()];  ~0'l,  
nEndPos = new long[bean.getNSplitter()]; IIn\{*|mW  
} x15tQb+  
r~2@#gTbl  
ZznWs+  
7%}3Ghc%  
} Ng39D#_)  
f EiEfu  
+;iesULXn  
public void run() :(p rx   
{ <({eOh5 N  
//获得文件长度 {]Iu">*  
//分割文件 U`p<lxRgQ  
//实例FileSplitterFetch _w/N[E  
//启动FileSplitterFetch线程 `LU,uz  
//等待子线程返回 uv!qE1z@':  
try{ ~S>ba']  
if(bFirst) ,UZE;lXJ'Q  
{ KJC9^BAr  
nFileLength = getFileSize(); _po 4(U&  
if(nFileLength == -1) L"IHyUW  
{ 0fK|}mmZA  
System.err.println("File Length is not known!"); I^Jp )k*z  
} GXK?7S0H  
else if(nFileLength == -2) &&S4x  
{ eRy'N|'  
System.err.println("File is not access!"); YY<?w  
} t8N9/DZ}Q  
else 1p<?S}zg@  
{ :tG".z  
for(int i=0;i<nStartPos.length;i++) K y2xWd8  
{ wXGFq3`  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); |M>k &p,B-  
} 4H? Ma|,  
for(int i=0;i<nEndPos.length-1;i++) CPeK0(7Zh  
{ HU+H0S~g  
nEndPos = nStartPos[i+1]; _rJ SkZO  
} Z_~DTO2Qg  
nEndPos[nEndPos.length-1] = nFileLength; FEmlC,%  
} gj;G:;1m  
} uWj-tzu  
qm5pEort  
j77}{5@p  
//启动子线程 ~MQf($]  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q%1;{5   
for(int i=0;i<nStartPos.length;i++) T2;  9  
{ WA5kX SdIb  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), esFL<T  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [eP]8G\ W  
nStartPos,nEndPos,i); #7T={mh  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J5IJy3d  
fileSplitterFetch.start(); u.Yb#?  
} X*"O'XCA  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bd*(]S9d  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O~OWRJ@p  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", A3pQ?d[  
nEndPos = " + nFileLength); @BhAFv,7  
// fileSplitterFetch[nPos.length-1].start();  /?xn  
9cj-v}5j  
\^LR5S&  
//等待子线程结束 {/!Gh\i  
//int count = 0; vkgL"([_  
//是否结束while循环 Q^w]Nj(e_  
boolean breakWhile = false; pdiZ"pe  
"Oko|3  
[E7@W[xr  
while(!bStop) Jz0S2&  
{ =V 7w CW  
write_nPos(); KptLeb:Om  
Utility.sleep(500); .. TjEBp  
breakWhile = true; <F & hfy  
'B6H/d>  
bQjHQ"G  
for(int i=0;i<nStartPos.length;i++) hzo,.hS's  
{ :/l   
if(!fileSplitterFetch.bDownOver) 1&"1pH  
{ 0^Cx`xdX:  
breakWhile = false; S c Kfr  
break; tb\pjLB][  
} 8!>pFVNJf  
} AR3=G>hO,  
if(breakWhile) L"/ato  
break; D9C; JD  
CnYX\^Ow  
k>hZ  
//count++; k8V0-.UL}  
//if(count>4) Wh_c<E}&  
// siteStop(); CI'5JOqP  
}  E/;YhFb[  
\c}r6xOr  
V%=t2+  
System.err.println("文件下载结束!"); K$]B" s  
} ?%ntO]  
catch(Exception e){e.printStackTrace ();} x=N;>  
} 1<|I[EI  
P[i/o#  
P@?CQvMx  
//获得文件长度 ':$a6f &T  
public long getFileSize() eqCB2u"Jq  
{ R"([Y#>m  
int nFileLength = -1; ?0Zw ^a  
try{ _ 0E,@[  
URL url = new URL(siteInfoBean.getSSiteURL()); xII!2.  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]XyJ7esg  
httpConnection.setRequestProperty("User-Agent","NetFox"); So`"z[5  
{rLOAewr  
;A!i V |  
int responseCode=httpConnection.getResponseCode(); *2;3~8Y  
if(responseCode>=400) Cz)D3Df^  
{ T]2q >N  
processErrorCode(responseCode); kzXW<V9  
return -2; //-2 represent access is error R FiR)G ,  
} |-D.  
N2J!7uoQ  
2fB@zF  
String sHeader; S5TT  
e?WR={  
u*`GIRfWT  
for(int i=1;;i++) (p!AX<=z  
{ -<=< T@,  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wf1DvsJQl  
//Utility.log(in.readLine()); Qpq0j^\  
sHeader=httpConnection.getHeaderFieldKey(i); {*9i}w|2  
if(sHeader!=null) ?]N&H90^5  
{ Q-5wI$=  
if(sHeader.equals("Content-Length")) bmpB$@  
{ t+ ]+Gn  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,#l oVLy  
break; .*"IJD9  
} U+ =q_ <  
} rfoCYsX'  
else _Hk`e}}  
break; yI<'J^1C[  
} I|H mbTXa  
} i,T{SV  
catch(IOException e){e.printStackTrace ();} N0PX<$y  
catch(Exception e){e.printStackTrace ();} YeJdkt  
p4 PFoFo2  
pp jrm  
Utility.log(nFileLength); nv]64mL3  
|t_2AV  
3RUB2c4  
return nFileLength; {r)M@@[  
} ,P+&-}gn9  
m>_'f{&u  
m<4Lo0?nS  
//保存下载信息(文件指针位置) ZxW V ,s&p  
private void write_nPos() L6.R?4B   
{ /o2eKx  
try{ ."O(Ig[  
output = new DataOutputStream(new FileOutputStream(tmpFile)); i1C'  
output.writeInt(nStartPos.length); <0m;|Ai'W  
for(int i=0;i<nStartPos.length;i++) R?Qou!*]  
{ Kw|`y %~  
// output.writeLong(nPos); ZlzFmNe60  
output.writeLong(fileSplitterFetch.nStartPos); { L5m`-x  
output.writeLong(fileSplitterFetch.nEndPos); ~-/AKaK}  
} m/AN*` V  
output.close(); FCPbp!q6  
} /2@@v|QL  
catch(IOException e){e.printStackTrace ();} @ 2_&ti  
catch(Exception e){e.printStackTrace ();} w[&BY  
} vI@8DWs  
->(B: Cz  
79DC]48M  
//读取保存的下载信息(文件指针位置) 5Fl|=G+3@g  
private void read_nPos() C#R9Hlb  
{ ghl9gFFj  
try{ .^23qCs  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3'wBX  
int nCount = input.readInt(); p:jrqjLp  
nStartPos = new long[nCount]; )UJMmw\  
nEndPos = new long[nCount]; D[mYrWHpn  
for(int i=0;i<nStartPos.length;i++) jI%yi-<;  
{ <#-ERQw  
nStartPos = input.readLong(); )j]RFt  
nEndPos = input.readLong(); Lnzhs;7L  
} DH%X+r  
input.close(); .uP$M(?j  
} OZ6%AUot  
catch(IOException e){e.printStackTrace ();} 92i# It}-/  
catch(Exception e){e.printStackTrace ();} ~ocr^V{"<~  
} wHmEt ORo  
;b^@o,=  
e_I 8Jj4  
private void processErrorCode(int nErrorCode) ]rS+v^@QH  
{ C1J'. !  
System.err.println("Error Code : " + nErrorCode); -_3.]o/J  
} H;6V  
o>YR Kb  
2-4%h!  
//停止文件下载 qA30G~S  
public void siteStop() 5eYCnc9  
{ /[OMpP  
bStop = true; OX"`VE  
for(int i=0;i<nStartPos.length;i++) R+\5hI@ >i  
fileSplitterFetch.splitterStop(); };*5+XY^  
]%."  
&Lw| t_y  
} [o~w>,a  
} ZD/!C9:&.0  
//负责部分文件的抓取 ;p/@tr9  
**FileSplitterFetch.java 8c9_=8vw  
*/ &Ru6Yt0W  
package NetFox; Dz?F,g_  
c1`o3gb  
TsQMwV_h  
import java.io.*; l},%g%}iMU  
import java.net.*; p82qFzq#  
i=ba=-"Mt  
j{vzCRa>8  
public class FileSplitterFetch extends Thread { MI/1uw  
D"MNlm  
VioVtP0  
String sURL; //File URL KH;e)91  
long nStartPos; //File Snippet Start Position &zZSWNW  
long nEndPos; //File Snippet End Position ^%L$$V nG  
int nThreadID; //Thread's ID 'BC-'Ot  
boolean bDownOver = false; //Downing is over Y9WH%  
boolean bStop = false; //Stop identical iG ;6e~p  
FileAccessI fileAccessI = null; //File Access interface x~W&a*WNT  
()r DM@  
7G/"!ePW6`  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pO^ 6p%  
{ (<ejJPWT  
this.sURL = sURL; U5klVl  
this.nStartPos = nStart; R:E`  
this.nEndPos = nEnd; O/Fzw^  
nThreadID = id; vn8Ez6<27  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qRUz;M4  
} 'g#))y  
'D1@+FFU0  
b7$?'neH/.  
public void run() CB~&!MdMr  
{ &(K*TB|Om  
while(nStartPos < nEndPos && !bStop) f /jN$p  
{ Gqs8$[o  
hi37p1t   
cIgF]My*D@  
try{ K= 69z  
URL url = new URL(sURL); !} 1p:@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qRU8uu   
httpConnection.setRequestProperty("User-Agent","NetFox"); {M=tw  
String sProperty = "bytes="+nStartPos+"-"; a7+BAma<  
httpConnection.setRequestProperty("RANGE",sProperty); <Z vG&  
Utility.log(sProperty); =q._Qsj?fu  
o5)U3U1|  
A`@we  
InputStream input = httpConnection.getInputStream(); f.,-KIiF  
//logResponseHead(httpConnection); 9+L! A  
Q/< $ (Y  
)P$ IXA\  
byte[] b = new byte[1024]; Nk 7Q  
int nRead; P"- ,^?6  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X \h]N  
{ p5*i d5  
nStartPos += fileAccessI.write(b,0,nRead); 39OZZaWL  
//if(nThreadID == 1) Bp}<H<@  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cD{[rI E3  
} r6^DD$X  
]Z~H9!%t  
`0sa94H1[  
Utility.log("Thread " + nThreadID + " is over!"); IlwY5iL  
bDownOver = true; E_xpq  
//nPos = fileAccessI.write (b,0,nRead); mFvw s  
} H}:apRb  
catch(Exception e){e.printStackTrace ();} Bdq/Ohw|!  
} 7_JK2  
} )q#b^( v  
%1#5 7-  
hX;xbl  
//打印回应的头信息 ~oOOCB  
public void logResponseHead(HttpURLConnection con) [E=t{&t  
{ GE"#.J4z  
for(int i=1;;i++) tnp]wZ  
{ rtY0?  
String header=con.getHeaderFieldKey(i); n&@\[,B  
if(header!=null) Gs-'  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \ Xuu|]  
Utility.log(header+" : "+con.getHeaderField(header)); j88H3bi0  
else 7)[4|I  
break; iX4/;2B=,  
} 9m<>G3Jr  
} )2\6 Fy0S  
N 4Dyec\  
*iYs,4  
public void splitterStop() &359tG0@P  
{ nkv zv  
bStop = true; byd[pnI$H  
} GXsHc,  
x5{ zGv.j  
lT*Hj.  
} %GAEZH,2sG  
rQ/S|gG  
S9mj/GpL3  
/* e\/Lcng  
**FileAccess.java 6tP^_9njy  
*//文件访问(定位,写) Zr`:A$  
package NetFox; N2C^'dFj  
import java.io.*; XO\P4x :c  
8on2 BC2  
OrHnz981K  
public class FileAccessI implements Serializable{ H]YPMG<  
9!PJLI=D  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l^&#fz  
RandomAccessFile oSavedFile; U{HJNftdpm  
long nPos; sHKT]^7  
ca-|G'q  
1J^{h5?lU  
public FileAccessI() throws IOException -p9|l%W  
{ g,9o'fs`x  
this("",0); J8(v65  
} U2!9Tl9".  
{ImZ><xe/  
7j{SCE;  
public FileAccessI(String sName,long nPos) throws IOException J}lBK P:-*  
{ Z5\u9E"]  
oSavedFile = new RandomAccessFile(sName,"rw"); Zs)HzOP)9  
this.nPos = nPos; J,k9?nkY /  
oSavedFile.seek(nPos); ;Cm%<vW4!  
} 6EJ,czt(  
NO"=\Zn6  
]{Iy<  
public synchronized int write(byte[] b,int nStart,int nLen) )mJl-u[0+  
{ 4mUQVzV  
int n = -1; 7 zK%CJ  
try{ ~- JkuRJ\  
oSavedFile.write(b,nStart,nLen); lY0^Z  
n = nLen; &R>x;&Gj  
} b=.Ikt+y  
catch(IOException e) mM1\s>o  
{ D.4=4"qMi  
e.printStackTrace (); #~ UG9@a  
} p-r}zc9@  
'ym/@h7h  
r `VKb  
return n; ,H\EPmNHK  
} We_/:=  
|h@'~c  
79=w]y  
} o|(-0mWBQA  
C%0|o/Wi  
<e)3 j6F!  
/* &p`RKD  
**SiteInfoBean.java 5 J61PuH   
*/ Sr/"'w;  
package NetFox; D8qZh1w%A|  
5&\Q0SX(~  
#8QQZdC8`  
public class SiteInfoBean { ~~]L!P  
PL[7|_%  
1\TXb!OtL  
private String sSiteURL; //Site's URL kuqf(  
private String sFilePath; //Saved File's Path RL SP?o2J  
private String sFileName; //Saved File's Name Gr}Lp  
private int nSplitter; //Count of Splited Downloading File s=#3f3  
>y &9!G  
H~e;S#3_v  
public SiteInfoBean() &%$r3ePwc  
{//nSplitter的缺省值为5 ci <`*>l  
//default value of nSplitter is 5 /9QI^6& SX  
this("","","",5); *O+G}_}  
} ;*[nZV>  
1Y_Cd  
A90o X1l  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ZC@sUj"  
{ $RfM}!7?  
sSiteURL= sURL; XL1v&'HLV  
sFilePath = sPath; E?m(&O j  
sFileName = sName; M`-.0  
this.nSplitter = nSpiltter; cF7I  
5VDqx@(  
%tT&/F  
} 5^~%10=  
|x3.r t  
m(L]R(t  
public String getSSiteURL() 51u8.%{4  
{ 06|+ _  
return sSiteURL; `B}( Ln  
} %+ynrg-  
_pnJ/YE  
3.Oc8(N^}  
public void setSSiteURL(String value) y'(l]F1]  
{ PF+v[h;,  
sSiteURL = value; " qY Pi  
} G'{$$+U^K  
mp:%k\cF|  
7y1J69IK  
public String getSFilePath() mzLDZ# =b  
{ I9-vV>:z  
return sFilePath; C0eP/d  
} _@3@_GE  
nlQ<Aa-%  
C0|<+3uND=  
public void setSFilePath(String value) '5\7>2fI  
{ @kw#\%Uz  
sFilePath = value; %6}S1fuA  
} \BOZhXfl'  
'8R5?9"  
wuSp+?{5k  
public String getSFileName() u=JI 1  
{ RcIGIt  
return sFileName; t."hAvRL  
} Dm?>U1{   
rV>/:FG  
fgVeB;k|  
public void setSFileName(String value) [#S}L(  
{ H|T!}M>  
sFileName = value;  I0trHrX9  
} G%_6" s  
- |n\  
.{%~4$yu7  
public int getNSplitter() gDU~hv  
{ t84(kzcC  
return nSplitter; 5-3`@ (/  
} ]PJb 9$f2  
UE^_SZ  
tkx1iBW=  
public void setNSplitter(int nCount) ;3wj(o0  
{  P#m/b<  
nSplitter = nCount; # Y/ .%ch.  
} c%%r  
} xs_l+/cZ  
zA4m !l*eM  
BQq,,i8H  
/* b1Bu5%bt,:  
**Utility.java `@eo <6  
*/ =LEKFXqM  
package NetFox; WD c2Qt  
l ps 6lnh  
{-;lcOD  
public class Utility { *)+1BYMo  
Z".mEF-b  
1sKKmtgH  
public Utility() 8q*MhH>6I  
{ 22lC^)`TE  
eq +t%  
vcTWe$;Q  
} R r7r5  
6yEYX'_  
//线程睡眠 Z |wM  
public static void sleep(int nSecond) 7 \)OWp  
{ LnZzY0  
try{ P[{qp8(g  
Thread.sleep(nSecond); {?tK]g#  
} /c/t_xB  
catch(Exception e) Y Y4"r\V  
{ E=!=4"rZF  
e.printStackTrace (); $@k[Xh  
} 8;2UP`8s?  
} j. UQLi&`  
O9y4.`a"  
//日志 dm;H0v+Y'  
public static void log(String sMsg) CMI'y(GN  
{ xE%1C6~C<  
System.err.println(sMsg); OL+dx`Y  
} 8`Wj 1 ,q  
q0|u vt"  
pm$ZKM  
public static void log(int sMsg) u%n6!Zx  
{ +76{S_CZ  
System.err.println(sMsg); V mxVE=l  
} ]C.x8(2!f  
} U^jxKBq^  
qFEGV+  
1n}q6oa=  
/* WmU5YZ(mAq  
**TestMethod.java WXz'H),R  
*/ ;M,u,KH)/  
package NetFox; C? pi8Xg  
+-_71rJc.  
eZDqW)x  
public class TestMethod { :B(F ?9qK  
o+(>/Ou  
,nn5LQ|l.j  
public TestMethod() `m2e *  
{ ///xx/weblogic60b2_win.exe 52+;j[ ]/O  
try{ !<9sOvka{  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2kg<O%KA`c  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "E`;8SZa  
SiteFileFetch fileFetch = new SiteFileFetch(bean); %ux%=@%  
fileFetch.start(); QoZ7l]^  
} -dX{ R_*  
catch(Exception e){e.printStackTrace ();} |Z%I3-z_DS  
h{zE;!+)D  
/Mk85C79  
} @**@W[EM  
a& >(*PQ  
ua$H"(#c  
public static void main(String[] args) Q y(Gy'q~  
{ sj;8[Xy's  
new TestMethod(); >7@kwj-f)  
} $Pa7B]A,Ae  
} uK6_HvHuy  
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