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http断点续传简单实现(java)

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/* (q 7;/n  
**SiteFileFetch.java k"dE?v\cG  
*/ T8LvdzS  
package NetFox; kVWrZ>McK  
import java.io.*; S]ndnxy"b  
import java.net.*; $m.'d*e5  
z xv y&  
k?pNmKVJM  
public class SiteFileFetch extends Thread { K:4 G(?w  
S-6i5H"B&  
P'5Lu  
SiteInfoBean siteInfoBean = null; //文件信息Bean C>l (4*S  
long[] nStartPos; //开始位置 ]w)uo4<^J  
long[] nEndPos; //结束位置 (s1iYK  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 UQ e1rf  
long nFileLength; //文件长度 GYT0zMMf  
boolean bFirst = true; //是否第一次取文件 y#ON=8l  
boolean bStop = false; //停止标志 ;rh =63g  
File tmpFile; //文件下载的临时信息 i+-=I+L3  
DataOutputStream output; //输出到文件的输出流 kad$Fp39  
" H=fWz5z  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) VF-[O  
public SiteFileFetch(SiteInfoBean bean) throws IOException ojWf]$^y}  
{ ^*NOG\BK@  
siteInfoBean = bean; C`oB [  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); %&O'>L  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); GO#eI]>/r  
if(tmpFile.exists ()) &6Wim<*  
{ F0'o!A#|(  
bFirst = false; + L 5  
read_nPos(); j,_{f =3;  
} f`J[u!Ja  
else s;[64ca]Q  
{ 7z&^i-l.  
nStartPos = new long[bean.getNSplitter()]; \Zk<|T61$  
nEndPos = new long[bean.getNSplitter()]; ^^Q> AfTR.  
} ||Wg'$3  
,(yaWd6  
]G~u8HPH!m  
j1@PfKh  
} {>&M:_`k  
'xOH~RlE  
:)Nk  
public void run() v@!r$jZ  
{ 6 1K:SXj  
//获得文件长度 zt )WX9  
//分割文件 7sJGB^vM  
//实例FileSplitterFetch n{F&GE="  
//启动FileSplitterFetch线程 4,6?sTuX  
//等待子线程返回 0?g&<q  
try{ Sj'.)nz>  
if(bFirst) $)O\i^T  
{ 49#?I:l  
nFileLength = getFileSize(); 41XXL$  
if(nFileLength == -1) b@1";+(27  
{ P6ugbq[x#e  
System.err.println("File Length is not known!"); SQ`ec95',  
} TkjZI}]2  
else if(nFileLength == -2) +m6acu)N.  
{ kL}*,8s{  
System.err.println("File is not access!");  YP}r15P  
} )% ?SWuS?N  
else 52Q~` t7F  
{ QTI^?@+N>  
for(int i=0;i<nStartPos.length;i++) Z5>}  
{ w >#.id[k  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); zU>bT20x/  
} 8x6{[Tx   
for(int i=0;i<nEndPos.length-1;i++) ViG-tb   
{ =$%_asQJ  
nEndPos = nStartPos[i+1]; \o!B:Vb<  
} cp 7;~i3  
nEndPos[nEndPos.length-1] = nFileLength; EG!):P  
} 771r(X?Fa  
} C'0=eel[  
}D#[yE,=\  
q}7(w$&  
//启动子线程 fL R.2vJ  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U[l{cRT   
for(int i=0;i<nStartPos.length;i++) Z|Xv_Xo|4  
{ `lq[6[n  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yNmzRH u  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q\v^3u2;m`  
nStartPos,nEndPos,i); @$d_JwI  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c:z<8#A}  
fileSplitterFetch.start(); q0]Z` <w  
} *6*/kV? F  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p[gq^5WuC  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J|I&{  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e;)&Hc:Z  
nEndPos = " + nFileLength); ,n+~S^r  
// fileSplitterFetch[nPos.length-1].start(); ,1-#Z"~c  
SSI('6Z/  
#kDJ>r |&-  
//等待子线程结束 ,!g%`@u  
//int count = 0; <)9E.h  
//是否结束while循环 <q#/z&F!  
boolean breakWhile = false; ?f[U8S}  
O0#9D'{  
~ f>km|Q{u  
while(!bStop) < {dV=  
{ @8 GW?R  
write_nPos(); 5l(Q#pSX  
Utility.sleep(500); O_wRI\ !  
breakWhile = true; :>otlI<0t  
q'awV5y  
(!`]S>_w9  
for(int i=0;i<nStartPos.length;i++) #AUz.WHD  
{ v/lQ5R1  
if(!fileSplitterFetch.bDownOver) B&)o:P7h  
{ !;^TW$ G  
breakWhile = false; %]i("21  
break; UKxeN[fv  
} >T~d uwS  
} -( ,iwF b  
if(breakWhile) \a\ApD  
break; JmK[7t  
BPzlt  
{]\!vG6  
//count++; 14v,z;HXj  
//if(count>4)  =:-x;  
// siteStop(); YV0K&d  
} bfjtNF*^  
BWN[>H %S  
S7 Tem:/  
System.err.println("文件下载结束!"); 2r=A'  
} FO5'<G-  
catch(Exception e){e.printStackTrace ();} !EQMTF=(  
} v(tr:[V  
<+c6CM$#}V  
7&z`N^dz{  
//获得文件长度 "ewB4F[  
public long getFileSize() 9>"To  
{ kdry a  
int nFileLength = -1; f#9\&-h e0  
try{ 5#U*vGVT  
URL url = new URL(siteInfoBean.getSSiteURL()); UF00K1dbz  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,HQaS9vBQ  
httpConnection.setRequestProperty("User-Agent","NetFox"); 0vRug|}k#%  
aGz <Yip  
qrmJJSJ  
int responseCode=httpConnection.getResponseCode(); b 64~Y|8  
if(responseCode>=400) l1qWl   
{ =,=tSp  
processErrorCode(responseCode); y$e'-v  
return -2; //-2 represent access is error G_] (7  
} oLXQ#{([  
D'823,-).  
CdRgI^5  
String sHeader; c*g(R.!  
]+B#SIC;  
:8~*NSEFd  
for(int i=1;;i++) 3[L)q2;}$N  
{ &v^LxLt+s  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E}$K&<J'-  
//Utility.log(in.readLine()); -l!;PV S|  
sHeader=httpConnection.getHeaderFieldKey(i); QDC]g.x  
if(sHeader!=null) >Cjb|f3'i}  
{ @:s|X  
if(sHeader.equals("Content-Length")) >aZ$x/U+Iw  
{ Qx mVImn"  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); FFNv'\)  
break; |h,aV(Q  
} 04wmN  
} uz1t uX_  
else W1s4[rL!Ht  
break; m"!!)  
} v?\bvg\E  
} 5"[Qs|VjA6  
catch(IOException e){e.printStackTrace ();} %@{);5[  
catch(Exception e){e.printStackTrace ();} DaW_-:@s  
UUx0#D/U0C  
,z?Re)q m  
Utility.log(nFileLength); 'lU9*e9  
=B(zW .Gf  
*p.P/w@1  
return nFileLength; bqMoO7&c  
} c4R6E~S  
r)dT,X[}F  
$ #C$V>  
//保存下载信息(文件指针位置) @^vVou_  
private void write_nPos() tF)aNtX4^  
{ =^P<D&%q  
try{ =J,aBp  
output = new DataOutputStream(new FileOutputStream(tmpFile)); _AQ :<0/#  
output.writeInt(nStartPos.length); ~h;c3#wuc  
for(int i=0;i<nStartPos.length;i++) ^z$-NSlI  
{ eA>O<Z1>  
// output.writeLong(nPos); IiACr@[?e  
output.writeLong(fileSplitterFetch.nStartPos); :Q\b$=,:  
output.writeLong(fileSplitterFetch.nEndPos); Xv'M\T}6C+  
} bf `4GD(  
output.close(); b0i]T?#  
} E#_TX3B   
catch(IOException e){e.printStackTrace ();} )#r]x1[Kn  
catch(Exception e){e.printStackTrace ();} G Cx]VN3 &  
} o_<o8!]l"  
#Vanw!  
v.+-)RLQg  
//读取保存的下载信息(文件指针位置) YSt']  
private void read_nPos() ~_SV `io  
{ Z8Fbx+~"  
try{ LD WFc_  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); D a)[mxJ  
int nCount = input.readInt(); CCX\"-C  
nStartPos = new long[nCount]; [t /hjm"$  
nEndPos = new long[nCount]; g[j"]~  
for(int i=0;i<nStartPos.length;i++) :JSOj@s  
{ m5sgcxt/  
nStartPos = input.readLong(); +GWeu0b(~  
nEndPos = input.readLong(); -lyT8qZ:(  
} &gkloP @  
input.close(); pd,5.d  
} Gu&?Gn oc  
catch(IOException e){e.printStackTrace ();} fw_V'l#\  
catch(Exception e){e.printStackTrace ();} ^zQ;8)ng  
} U]fE(mpI9  
pHY~_^B4&  
)[6H!y5  
private void processErrorCode(int nErrorCode) z4 8,{H6h  
{ v\t$. _at  
System.err.println("Error Code : " + nErrorCode); LI?rz<H!D  
} o\8yYX  
0?ZJJdI3  
_ 9Tv*@  
//停止文件下载 <?,o {  
public void siteStop() *;O$=PE  
{ ;*+jCL 2F  
bStop = true; VZJs@qx:Z  
for(int i=0;i<nStartPos.length;i++) |J2R w f  
fileSplitterFetch.splitterStop(); (hVhzw"~  
CJ&0<Z}{m  
l.lXto.6)  
} gmWRw{nS+  
} )2z (l-$.  
//负责部分文件的抓取 VVvV]rU~  
**FileSplitterFetch.java L!DP*XDp  
*/ ?DkMzR)u  
package NetFox; eQno]$-\  
H__9%p#  
~d 7!)c`z  
import java.io.*; [X=-x=S,  
import java.net.*; w:& m_z#M  
X #-U  
AU$W=Z*  
public class FileSplitterFetch extends Thread { &?/h#oF@\  
%K /=7  
k#ED#']N  
String sURL; //File URL :sFP{rFx~  
long nStartPos; //File Snippet Start Position RT8xU;   
long nEndPos; //File Snippet End Position G1vWHa7n;f  
int nThreadID; //Thread's ID mKPyM<Q  
boolean bDownOver = false; //Downing is over L\5j"] }`  
boolean bStop = false; //Stop identical Ezm ~SY  
FileAccessI fileAccessI = null; //File Access interface 1/3Go97/qV  
B+wSLi(  
Io{)@H"f  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .3A66 O~zT  
{ Wj/.rG&tE  
this.sURL = sURL; $k V^[  
this.nStartPos = nStart; KDuM;  
this.nEndPos = nEnd; ykxjT@[  
nThreadID = id; ]0zXpMNI  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?z171X0  
} k(><kuJ`3  
U"A]b(54  
'AE)&56  
public void run() r@H<@Vuc  
{ ITRv^IlF  
while(nStartPos < nEndPos && !bStop) iQZgs@  
{ m]+g[L?-  
Xp{+){Iu  
"44VvpQC  
try{ 0ho+Y@8  
URL url = new URL(sURL); +%=Ao6/#  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();  "C B*  
httpConnection.setRequestProperty("User-Agent","NetFox"); @/ wJW``;  
String sProperty = "bytes="+nStartPos+"-";  RN'|./N  
httpConnection.setRequestProperty("RANGE",sProperty); M&~3fRb 4  
Utility.log(sProperty); lKrD.iYt8  
OnC|9  
]ZelB,7q  
InputStream input = httpConnection.getInputStream(); amK?LDf]  
//logResponseHead(httpConnection); A jr]&H4  
ce/Rzid  
bPAp0}{Fu  
byte[] b = new byte[1024]; xXE/pIXw  
int nRead; PtCwr)B,  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -wy$ ?Ha  
{ k+{ -iPm{  
nStartPos += fileAccessI.write(b,0,nRead); 0iinr:=u  
//if(nThreadID == 1) T/V8&'^i  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gd R wh  
} ^TJn&k  
Xlpu_H|  
KRf$VbuL  
Utility.log("Thread " + nThreadID + " is over!"); t]#y} V  
bDownOver = true; x^qmYX$'1b  
//nPos = fileAccessI.write (b,0,nRead); ><viJ$i  
} WQ<J<$$uu  
catch(Exception e){e.printStackTrace ();} { ,/mQ3  
} 3 ~0Z.!O  
} iJk`{P_  
z[B*sbS  
QDRSQ[\  
//打印回应的头信息 ^!L'Ao y;E  
public void logResponseHead(HttpURLConnection con) Ka&[ Oz<w  
{ q%w\UAqA  
for(int i=1;;i++) W^i ct,t  
{ nKp='>Th  
String header=con.getHeaderFieldKey(i); Vz!W(+  
if(header!=null) !krbGpTVH  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ce\]o^4  
Utility.log(header+" : "+con.getHeaderField(header)); p3`'i  
else P}KN*Hn.  
break; 5vj;lJKcd`  
} iv2did4  
} x'{L%c>L  
)C5<puh  
m:59f9WXA  
public void splitterStop() :D8V*F6P  
{ ='q:Io?T  
bStop = true; k)UF.=$d  
} %g{m12  
w?d~c*4+  
 #:_qo  
} ya0L8`q  
!jL|HwlA  
UB }n=  
/* 8rAOs\ys  
**FileAccess.java ^6bU4bA  
*//文件访问(定位,写) 8bLA6qmM\  
package NetFox; cu5Yvp  
import java.io.*; "jH=O(37  
OW- [#r  
eEePK~%c  
public class FileAccessI implements Serializable{ r t@Jw]az  
fpJM)HU  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vyP3]+n  
RandomAccessFile oSavedFile; w>>)3:Ytd  
long nPos; dR<sBYo  
EYtf>D  
w$WN` =  
public FileAccessI() throws IOException 9"Oz-!Y4  
{ lG/M%i  
this("",0); G.OAzA13!t  
} eVyXh>b*  
wWv")dk3i  
3JVENn9  
public FileAccessI(String sName,long nPos) throws IOException T&c0j(  
{ /L\ ]t  
oSavedFile = new RandomAccessFile(sName,"rw"); =T;>$&qs  
this.nPos = nPos; D0 Yl?LU3  
oSavedFile.seek(nPos); ^AkVmsv;;  
} 0)`{]&  
"K n JUXpl  
HgPRz C  
public synchronized int write(byte[] b,int nStart,int nLen) u@tJu'X  
{ 6:O3>'n  
int n = -1; j}7as&  
try{ ||a 5)D  
oSavedFile.write(b,nStart,nLen); dqMt6b\}  
n = nLen; yBqv'Y  
} P,r9  <  
catch(IOException e) y|f`sBMM  
{ aG.j0`)%  
e.printStackTrace (); 7p%W)=v  
} k nrR%e;  
6FNs4|(d  
++d(}^C;  
return n; xdb9oH  
} wNMgY  
AuuZWd  
<7N8L  
} qR^KvAEQSo  
DFKFsu8s  
4A6D>ChB'E  
/* Vw.c05x  
**SiteInfoBean.java X~|P  
*/ @FVan  
package NetFox; ~WXT0-,  
NSH20$A<  
}_93}e  
public class SiteInfoBean { B?`n@/  
rqbX9M^  
_9!*laR!2  
private String sSiteURL; //Site's URL N=FU>qbz  
private String sFilePath; //Saved File's Path p?(w !O  
private String sFileName; //Saved File's Name Y^80@MJ  
private int nSplitter; //Count of Splited Downloading File hT4 u;3xE  
gdkl,z3N3  
q$FwO"dC  
public SiteInfoBean() bh9rsRb}O  
{//nSplitter的缺省值为5 k~f3~-"  
//default value of nSplitter is 5 /+2;".  
this("","","",5); &~VWh}=r  
} ]vj4E"2;  
q}gj.@Q"  
fq(r,h=|  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4Kjrk7GAx  
{ vFz%#zk>  
sSiteURL= sURL; e=K2]Y Q{  
sFilePath = sPath; PkA_uDhw  
sFileName = sName; gM_z`H 5[!  
this.nSplitter = nSpiltter; R\k= CoJJ  
pwo5Ij,~q  
?&#z3c$}  
} -;pZC}Nd3  
a)J3=Z-  
#v!(uuq,  
public String getSSiteURL() EOJk7  
{ NX7(;02  
return sSiteURL; lg` Qi&  
} >;V ? s]  
y,&.<Yc  
b<,Z^Z_  
public void setSSiteURL(String value) ]"bkB+I  
{ jO xH' 1I  
sSiteURL = value; `L p3snS  
} XQL"D)fw  
#?%akQ+w  
KWtLrZ(j  
public String getSFilePath() .w5#V|   
{ k8fvg4  
return sFilePath; o=i)s2   
} +E8 \g  
)6mx\t  
n';"c;Ye)  
public void setSFilePath(String value) -L e:%q2  
{ 3=o^Vv  
sFilePath = value; !z@QoD  
} =f'MiU!p6  
*zoAD|0N  
Fx#0 :p  
public String getSFileName() )=VSERs  
{ K..L8#SC  
return sFileName; )o!y7MTl  
} 86Q\G.h7  
}#~@HM>6Z  
U-.?+ `  
public void setSFileName(String value) p&1IK8i"  
{ v&g(6~b_>  
sFileName = value; klHOAb1  
} APxy %0Q  
i! G^=N  
vt{s"\f  
public int getNSplitter() ;0*T7l  
{ 9y=$ |"<(  
return nSplitter; K07SbL7g!p  
} _nw=^zS  
{SH +lX0]{  
'VA\dpa{J  
public void setNSplitter(int nCount) ,arFR'u>  
{ }'HJVB_  
nSplitter = nCount; w)I!q&`Y  
} U9:?d>7  
} z 9mmZqhK\  
~F7 +R   
#PYTFB%  
/* n]&/?6}  
**Utility.java hpJ[VKe  
*/ MGn:Gj"d  
package NetFox; O+Z[bis`  
9( ;lcOz  
a<+Qw'  
public class Utility { $<^4G  
]'Y vI! r  
0gNwC~IA8  
public Utility() I}oxwc  
{ [\N,ow,n  
b 62 o  
.<JD'%?"  
} rAqg<fR*  
(1e;7sNG@  
//线程睡眠 + >o/Ob  
public static void sleep(int nSecond) e-<fkU9^W  
{ q 4_&C&7  
try{ ,ry2J,IT7  
Thread.sleep(nSecond); x:8xGG9  
} M7vc/E}]n  
catch(Exception e) ,=KJ7zIK?  
{ }N; c  
e.printStackTrace (); :32  
} M ,.++W\  
} 9:0JWW^so  
`o(PcX3/}  
//日志 e9r#r~Qq|  
public static void log(String sMsg) 2GRh8G&5  
{ EgIFi{q=0  
System.err.println(sMsg); xQs2 )  
} 2%g)0[1  
@D K,ka(  
eK\ O>  
public static void log(int sMsg) 6L@g]f|Y@  
{ =!3G,qV  
System.err.println(sMsg); {UT>> *C  
} $?p^ m`t_  
} N>;"r]Rl"  
$x;wnXXXM  
,ZjbbBZ  
/* rlu{C4l  
**TestMethod.java {xr!H-9ZAA  
*/ ^!^8]u<Q  
package NetFox; `WF?87l1  
mj :8ZZ  
b\~rL,7(  
public class TestMethod { qA:CV(Z  
. (*V|&n  
H~RWM'_  
public TestMethod() 2&fIF}vk>m  
{ ///xx/weblogic60b2_win.exe vW6Pf^yJ  
try{ Vf6lu)Z c1  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mJb>)bO l  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pLMki=.Ld  
SiteFileFetch fileFetch = new SiteFileFetch(bean); '/ 3..3k  
fileFetch.start(); Uxx=$&#  
} K' N`rx.7  
catch(Exception e){e.printStackTrace ();} |;{^Mci%  
c>d+q9M  
`.nkC_d  
} jeMh  
#: L|-_=a  
'7[{ISBXU  
public static void main(String[] args) En 3Q%  
{ @TC_XU)&  
new TestMethod(); YhFB*D;  
} c_a*{L|c  
} Bn*D<<{T  
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