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http断点续传简单实现(java)

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/* J}J7A5P  
**SiteFileFetch.java bem-T`>'  
*/ 7JHS8C<]  
package NetFox; ,3E9H&@j  
import java.io.*; XT0:$0F  
import java.net.*; t?:Q  
 V_-{TGKX  
#J<IHNRt  
public class SiteFileFetch extends Thread { nfbqJ  
&9F(uk=X  
T^~9'KDd  
SiteInfoBean siteInfoBean = null; //文件信息Bean :[ AP^  
long[] nStartPos; //开始位置 e=%6\&q  
long[] nEndPos; //结束位置 `[zd  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 }./_fFN@  
long nFileLength; //文件长度 ?Ok@1  
boolean bFirst = true; //是否第一次取文件 2?bE2^6  
boolean bStop = false; //停止标志 d$(>=gzBQ  
File tmpFile; //文件下载的临时信息  {!9i8T  
DataOutputStream output; //输出到文件的输出流 wu2C!gyBo  
ST[+k  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 2>bV+[@B  
public SiteFileFetch(SiteInfoBean bean) throws IOException #RA3 T[A  
{ ~8 w(M  
siteInfoBean = bean; r06M.r   
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 0{ ;[k  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ?dcR!-3  
if(tmpFile.exists ()) q"Z!}^{  
{ WgK|r~  
bFirst = false; QP?Deltp  
read_nPos(); w(xRL#%  
} 5Si\hk:o  
else 'o*:~n  
{ _noQk3N  
nStartPos = new long[bean.getNSplitter()]; \"u3 x.!  
nEndPos = new long[bean.getNSplitter()]; g}]EIv{  
} XN=Cq*3}  
66+y@l1  
MN22#G4j^w  
m*^|9*dIC  
} mzX <!  
l6S6Y  
&PAgab2$  
public void run()  !&Z,ev  
{ U5z}i^8a  
//获得文件长度 {)vue0 vP  
//分割文件 2%DleR'i  
//实例FileSplitterFetch gxku3<S  
//启动FileSplitterFetch线程 EdPN=  
//等待子线程返回 F|DKp[<]8  
try{ OJ'x>kE  
if(bFirst) oe5.tkc  
{ h1 D#,  
nFileLength = getFileSize(); oYG].PC  
if(nFileLength == -1) gAY%VFBP0  
{ dTV:/QM  
System.err.println("File Length is not known!"); O(( kv|X4  
} `=0J:  
else if(nFileLength == -2) ~',}]_'oR-  
{ $qx&\@O  
System.err.println("File is not access!"); Sl{nS1q  
} -*K!JC-  
else dLSnhZ  
{ B az:N 6u  
for(int i=0;i<nStartPos.length;i++) s\`Vr;R:|  
{  yq ?_#r  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); _0rHxh7}q  
} $VrKoL\ScA  
for(int i=0;i<nEndPos.length-1;i++) 2 8j=q-9Z  
{ `37GVo4  
nEndPos = nStartPos[i+1]; | 3`qT#p{  
} ?]=fC{Rh  
nEndPos[nEndPos.length-1] = nFileLength; lK? Z38  
} / h6(!-"  
} Y"uFlHN&i  
Jb~-)n2  
D k'EKT-  
//启动子线程 xmDX1sL**  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ohm>^N;  
for(int i=0;i<nStartPos.length;i++) >q&Q4E0  
{ =oF6|\]{ ;  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZHs hg`I`  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Te8BFcJG  
nStartPos,nEndPos,i); id-VoHd K  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !j(KbAhWZ  
fileSplitterFetch.start(); MGO.dRy_  
} c#G]3vTdE  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n(Up?_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $l&&y?()  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~?}/L'q!b  
nEndPos = " + nFileLength); }eX_p6bBw  
// fileSplitterFetch[nPos.length-1].start(); X*~NE\  
! 40t:+I  
v`hv5wQ  
//等待子线程结束 ] %*970  
//int count = 0; H&L=WF+x  
//是否结束while循环 vtFA#})~  
boolean breakWhile = false; oT5xe[{yj  
#^Dc:1,  
SPV'0* Z  
while(!bStop) j8os6I  
{ 3D~Fu8Hg1  
write_nPos(); '3o0J\cz  
Utility.sleep(500); B-[SUmHr  
breakWhile = true; s\&_Kbw] c  
 W4CI=94  
$/C<^}A  
for(int i=0;i<nStartPos.length;i++) oQDOwM,  
{ JLAg-j2  
if(!fileSplitterFetch.bDownOver) #{0DpSzE5  
{ c 3@SgfKmk  
breakWhile = false; Vk_*]wU  
break; ^c]Sl  
} L\og`L)5\  
} ZZC= 7FB  
if(breakWhile) dW7dMx  
break; 1A- 8,)  
Hcd>\0  
+29;T0>a  
//count++; T , =ga  
//if(count>4) Za!c=(5  
// siteStop(); DuvP3(K  
} ud:?~?j&w  
U30)r+&  
V8Q#%#)FHe  
System.err.println("文件下载结束!"); 5?kA)!|UB  
} 8{+~3@T  
catch(Exception e){e.printStackTrace ();} @sKAsn  
} 16N8h]l  
`Ik}Xw  
73~Mq7~8  
//获得文件长度 |->y'V  
public long getFileSize() UKK}$B  
{ &SN$D5U'  
int nFileLength = -1; (P#2Am$  
try{ i`] M2Q   
URL url = new URL(siteInfoBean.getSSiteURL()); ,:\2Lf  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); na']{a 1K  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;(0:6P8I  
k7{fkl9|#  
ga^<_;5<  
int responseCode=httpConnection.getResponseCode(); *gz{:}NX  
if(responseCode>=400) xN"KSQpu  
{ \Di~DN1  
processErrorCode(responseCode); <vt^=QA'  
return -2; //-2 represent access is error )dL?B9d:  
} rF0zGNH  
($(1KE  
*vAOUqX`x  
String sHeader; e3>Re![_.  
-N\{QX1Yd  
nv$  
for(int i=1;;i++) )Elr8XLw  
{ L7Oytdc<  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /#G"'U/  
//Utility.log(in.readLine()); {t/!a0\HS  
sHeader=httpConnection.getHeaderFieldKey(i); >qF KXzI  
if(sHeader!=null) vWkKNB  
{ [ !R%yD;  
if(sHeader.equals("Content-Length")) wCt+{Y3T  
{ LVEVCpp@  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <$yer)_J!k  
break; ,IJNuu\  
} .hJ8K #r  
} _SP u`=~K  
else d7^XP  
break; 8e\v5K9  
} ABHZ)OM  
} CLkVe  
catch(IOException e){e.printStackTrace ();} 0KQ8; &a|  
catch(Exception e){e.printStackTrace ();} rbtV,Y  
4P~<_]yf  
\~)573'  
Utility.log(nFileLength); GO)rpk9  
BkZ%0rw%  
KncoIw  
return nFileLength; 'j)eqoj  
} D1Sl+NOV  
'j3'n0o  
P~qVr#eU  
//保存下载信息(文件指针位置) &"kx (B  
private void write_nPos() &V:dcJ^Q  
{ ]czy8n$+  
try{ )[K3p{4  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;&!dD6N  
output.writeInt(nStartPos.length); #] GM#.  
for(int i=0;i<nStartPos.length;i++) UKJY.W!w4  
{ rOD KM-7+  
// output.writeLong(nPos); \fKE~61  
output.writeLong(fileSplitterFetch.nStartPos); `P5"5N\h  
output.writeLong(fileSplitterFetch.nEndPos); ZkIQ-;wx  
} LuqaGy}>-  
output.close(); .)3 2WD%  
} {;}8Z$  
catch(IOException e){e.printStackTrace ();} YQ)m?=+J  
catch(Exception e){e.printStackTrace ();} i@J,u  
} 8 KkpXaz  
Vx*q'~4y!|  
\;6F-0  
//读取保存的下载信息(文件指针位置) &rd(q'Vi  
private void read_nPos() I>5@s;  
{ $ B9=v  
try{ =@w:   
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xKr,XZu  
int nCount = input.readInt(); `SwnKg  
nStartPos = new long[nCount]; 0&\Aw'21  
nEndPos = new long[nCount]; heKI<[8l  
for(int i=0;i<nStartPos.length;i++) 2$o[  
{ 0/ Ht;(  
nStartPos = input.readLong(); 'oHR4O*  
nEndPos = input.readLong(); (Lo2fY5  
} 709eLhXrH  
input.close(); ,![=_d  
} mCGcM^21-x  
catch(IOException e){e.printStackTrace ();} XJzXxhk2  
catch(Exception e){e.printStackTrace ();} ".)_kt[  
} %yMzgk[u  
`-H:j:U{  
?W n(ciO  
private void processErrorCode(int nErrorCode) :65HMWy.  
{ W*<]`U_.  
System.err.println("Error Code : " + nErrorCode); <C$<(Dw5  
} jyGVbno`  
E%^28}dN  
yx2.7h3  
//停止文件下载 }SV3PdE  
public void siteStop() 6\3k0z  
{ [KH?5 C  
bStop = true; DOerSh_0W  
for(int i=0;i<nStartPos.length;i++) S0+zq<  
fileSplitterFetch.splitterStop(); upDQNG>d  
C' ._}\nX  
iW?9oe  
} 1,j9(m2  
} QP B"E W  
//负责部分文件的抓取 !T*B{+|  
**FileSplitterFetch.java _")h %)f  
*/ |&Pl4P  
package NetFox; m=MT`-:  
BB.TrQM.#  
\Wc/kY3&  
import java.io.*; >y9o&D  
import java.net.*; \`zG`f  
yU|ji?)e  
uB1!*S1f  
public class FileSplitterFetch extends Thread { fqb$_>3Ol  
C.E> )  
A7C+&I!L  
String sURL; //File URL Fw9``{4w  
long nStartPos; //File Snippet Start Position nEm7&Gb  
long nEndPos; //File Snippet End Position =.E(p)fz  
int nThreadID; //Thread's ID [bv@qBL  
boolean bDownOver = false; //Downing is over 9@Sb! 9h  
boolean bStop = false; //Stop identical &XRFX 5gP  
FileAccessI fileAccessI = null; //File Access interface l~YNmmv_  
3}21bL  
Yd;r8rN  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q=Yerp3~  
{ AfN   
this.sURL = sURL; f^4*.~cB  
this.nStartPos = nStart; d5y2Y/QO  
this.nEndPos = nEnd; C[nr>   
nThreadID = id; ? SP7vQ/  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9Nu#&_2R  
} |V\.[F2Fe  
j dhml%pAd  
 #U52\3G  
public void run() ]zU<=b@  
{ Sqf.#}u<=  
while(nStartPos < nEndPos && !bStop) K=x1m M+RK  
{ IKDjatn  
F[=lA"F^  
E$tk1SVo  
try{ +~Lzsh"  
URL url = new URL(sURL); htYrv5q=M  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -Y=c g;  
httpConnection.setRequestProperty("User-Agent","NetFox"); d:pm|C|F  
String sProperty = "bytes="+nStartPos+"-"; $pfe2(8  
httpConnection.setRequestProperty("RANGE",sProperty); $Ds]\j*  
Utility.log(sProperty); 8.Ef5-m  
?gwbg*  
6r=)V$K <  
InputStream input = httpConnection.getInputStream(); %]0U60  
//logResponseHead(httpConnection); &NjZD4m`=  
b*F~%K^i$  
~|{)h^]@  
byte[] b = new byte[1024]; sLa)~To  
int nRead; *rz(}(r  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L*01l"5  
{ l;}7A,u  
nStartPos += fileAccessI.write(b,0,nRead); ,beR:60)  
//if(nThreadID == 1) ,DuZMGg  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s<_LcQbt{  
} [RFK-E  
M(zY[O  
qb> r\bc  
Utility.log("Thread " + nThreadID + " is over!"); DgT.Lku?  
bDownOver = true; $;i$k2n:  
//nPos = fileAccessI.write (b,0,nRead); 60%~+oHi~  
} gDNTIOV  
catch(Exception e){e.printStackTrace ();} P9i9<pR  
} vDeG20.?Z  
} sQ:VrXwP  
y7)[cvB  
hf^`at  
//打印回应的头信息 FR,#s^kF  
public void logResponseHead(HttpURLConnection con) k\&IFSp  
{ <<On*#80w  
for(int i=1;;i++) 0S:!Gv +  
{ qVD!/;l  
String header=con.getHeaderFieldKey(i); @VC9gd O/  
if(header!=null) Qv0>Pf  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @52=3  
Utility.log(header+" : "+con.getHeaderField(header)); /N[o[q  
else RQS:h]?:l  
break; m)|.:sj  
} ZYR,8y  
} xDA,?i;T 0  
ok%a|Zz+]  
z?uQlm*We  
public void splitterStop() aRO_,n9  
{ @z$pPo0fW  
bStop = true; D0y,TF  
} `-K)K<  
m wEVEx24  
BRU9LS  
} .`Old{<  
qe6C|W~n  
_ U8OIXN  
/* 9Ajgfy>  
**FileAccess.java _/%]:  
*//文件访问(定位,写) FQ|LA[~  
package NetFox; n?e@):  
import java.io.*; o eJC  
Z!RRe]"y  
fyg~KF}  
public class FileAccessI implements Serializable{ &pMlt7  
snTJe[^d  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 IJ_ 'w[k  
RandomAccessFile oSavedFile; Pvg  
long nPos; Ro'4/{}+  
OZC/+"\,  
J!A/r<  
public FileAccessI() throws IOException {F(-s"1;xO  
{ Q9eYF-+  
this("",0); m['v3m:  
} jWv3O&+?X  
yNqm]H3<MP  
# McK46B z  
public FileAccessI(String sName,long nPos) throws IOException 71 L\t3fG  
{ m.HX2(&\3  
oSavedFile = new RandomAccessFile(sName,"rw"); -@ UN]K  
this.nPos = nPos; k;K> ,$ F  
oSavedFile.seek(nPos); z%}CB Tm  
} ]cLEuE^&  
~aqT~TL_  
{? K|(C  
public synchronized int write(byte[] b,int nStart,int nLen) D,GPn%Wqi  
{ <r7qq$  
int n = -1; e"o6C\c  
try{ M\y~0uZ  
oSavedFile.write(b,nStart,nLen); ?HEtrX,q  
n = nLen;  J:~[ j  
} p-Rm,xyL%  
catch(IOException e) -VreBKn  
{ 3lLW'g&=  
e.printStackTrace (); XUQW;H  
} oieQ2>lYh  
~.4W,QLuD  
u"#6_-0y  
return n; o&hKg#nO83  
} *3.yumcv{L  
I!F}`d  
,Ou1!`6?t  
} A"\P&kqMV  
f74%YY  
~ C/Yv&58  
/* e_I; y  
**SiteInfoBean.java 0uVk$\:i  
*/ oRT  
package NetFox; X ]pR,\B  
) 8x:x7?  
.y %pGi  
public class SiteInfoBean { y(/jTS/ hd  
Xc8= 2n  
JK(`6qB>(6  
private String sSiteURL; //Site's URL up+.@h{  
private String sFilePath; //Saved File's Path ?dJ/)3I%F  
private String sFileName; //Saved File's Name zt)p`kdD  
private int nSplitter; //Count of Splited Downloading File L)kb (TH  
(<]\,pP0_  
#51 4a(6  
public SiteInfoBean() pIZLGsu[  
{//nSplitter的缺省值为5 r6F{  
//default value of nSplitter is 5 >+Sv9S  
this("","","",5); e'k;A{Oh  
} ueWR/  
iioct_7,g<  
bxd3  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9:9N)cNvfX  
{ ?$30NK3G  
sSiteURL= sURL; .q5J^/kr  
sFilePath = sPath; 5 4ak<&?  
sFileName = sName; r3+<r<gs  
this.nSplitter = nSpiltter; aW`:)y&f  
zmy4tsmX  
0v_6cYA  
} L~*|,h  
xQNw&'|UU  
_dYf  
public String getSSiteURL() Xk{!' 0  
{ Z-^uM`],G  
return sSiteURL; ]+}ZfHp  
} ]~j_N^oZ1X  
pr62:  
(*Gi~?-  
public void setSSiteURL(String value) RL7C YB  
{ =F'l's^j  
sSiteURL = value; f nLR  
} + >T7Q`64  
vh9kwJyT  
b{~fVil$y  
public String getSFilePath() %+AS0 JhB  
{ Wphe%Of  
return sFilePath; ewb*?In  
} ntrY =Y  
8Zcol$XS'  
=&di4'`  
public void setSFilePath(String value) (l\a'3a.  
{ }G>v]bV0V  
sFilePath = value; Ez06:]Jd  
} c[(yU#@  
0OleO9Ua  
A5CdLwk  
public String getSFileName() i&A{L}eCr:  
{ a~8:rW^  
return sFileName; ]%gp?9wy  
} 33=Mm/<m$P  
x2 w8zT6M  
R'*<A3^  
public void setSFileName(String value) ^-gfib|VGe  
{ _v1bTg"?  
sFileName = value; -rE eKt  
} ljN zYg~-  
*0=fT}&!  
Nc G,0K  
public int getNSplitter() KotPV  
{ T{_1c oL  
return nSplitter; @PYW|*VS  
} E)KB@f<g*  
f:_=5e +  
Oq #o1>  
public void setNSplitter(int nCount) DY)D(f/&3  
{ n?y'c^  
nSplitter = nCount; ^c/mj9M#C  
} B1|?RfCe  
} y<O@rD8iA  
8B}'\e4i  
!a' K &  
/* IkSX\*  
**Utility.java e{v,x1Y_z(  
*/ p G)9=X!9  
package NetFox; P#AAOSlLV  
"V:   
v*&Uk '4E  
public class Utility { Vh 2Bz  
k%{ l4  
/6Y0q9  
public Utility() R ^HohB  
{ }BA9Ka#%  
/uK)rG F  
Bs_S.JP<`  
} KjO-0VMN3  
gsnP!2cR  
//线程睡眠 =hJfL}&O3  
public static void sleep(int nSecond) +2- qlU  
{ S$S_nNq  
try{ y:qx5Mi  
Thread.sleep(nSecond); }$^]dn@  
} %p<$|'  
catch(Exception e) CT|z[^  
{ (F/HU"C  
e.printStackTrace (); 6_W<hevI  
} smQ4CLJ  
} >NJjS8f5  
2K3MAd{  
//日志 EY So=  
public static void log(String sMsg) BTO A &Ag  
{ 0Xp nbB~~I  
System.err.println(sMsg); %_>Tcm=  
} 1#/6r :  
g+e:@@ug  
[6O04"6K  
public static void log(int sMsg) @XeEpDn]  
{ DNmb[  
System.err.println(sMsg); $"/UK3|d  
} DLU[<! C  
} VK9Q?nu  
5(423"(y  
Ud$Q0m&  
/* ])eOa%  
**TestMethod.java U9x4j_.q  
*/ pfR"s:#  
package NetFox; +eU`H[iu  
5f8"j$Az  
+Dd"41  
public class TestMethod { v5B" A"N  
R|-6o)$  
6*sw,sU[y  
public TestMethod() q1H~ |1  
{ ///xx/weblogic60b2_win.exe 9t#P~>:jY}  
try{ t @;WgIp(&  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7LG+$LEz  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mU>&ql?e  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Jms=YLIAA  
fileFetch.start(); expxp#S  
} q1STRYb   
catch(Exception e){e.printStackTrace ();} <]~ZPk[  
Og=[4?Kpk  
4e}{$s$Xx  
} *vb^N0P  
n|6?J_{<b>  
'm[6v}  
public static void main(String[] args) 2%5?F n=  
{ %Mh Q  
new TestMethod(); p<q].^M  
} ,6DD=w0r  
} }~rcrm.   
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