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http断点续传简单实现(java)

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/* )o " SB1  
**SiteFileFetch.java _H^^2#wc/  
*/ C,OB3y  
package NetFox; 3<KZ.hr  
import java.io.*; Y5h)l<P>B  
import java.net.*; ^-e3=&  
+H)!uLva B  
V',m $   
public class SiteFileFetch extends Thread { ^td!g1"<  
jt'Y(u]2  
S+_A <p  
SiteInfoBean siteInfoBean = null; //文件信息Bean 0] :*v?  
long[] nStartPos; //开始位置 J-eA,9J  
long[] nEndPos; //结束位置 9:CVN@E  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ~ X]"P4 u  
long nFileLength; //文件长度 o5*74Mv  
boolean bFirst = true; //是否第一次取文件 ?vht~5'  
boolean bStop = false; //停止标志 T(sG.%  
File tmpFile; //文件下载的临时信息 np'M4^E;  
DataOutputStream output; //输出到文件的输出流 evndw>  
dFI.`pB  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) y7;XOPm  
public SiteFileFetch(SiteInfoBean bean) throws IOException m5'__<  
{ :r vO8.\  
siteInfoBean = bean; DMK"Q#Vw  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); \0*yxSg,^  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 4Rrw8Bw  
if(tmpFile.exists ()) =CG!"&T  
{ \K_!d]I {  
bFirst = false; T,xVQ4J?  
read_nPos(); fr,CH{Uq  
} 6gg#Z  
else <750-d!  
{ <@x+N%C  
nStartPos = new long[bean.getNSplitter()]; :nbW.B3GV  
nEndPos = new long[bean.getNSplitter()]; $E4O^0%/p  
} X('Q;^`  
`3>)BV<P  
*xZQG9`kt  
e $/Zb`k  
} rvoS52XG,  
,h^;~|GT  
[hv3o0".  
public void run() 3$kv%uf{  
{ `aX}.{.!  
//获得文件长度 9TXm Z  
//分割文件 9%)& }KK|  
//实例FileSplitterFetch 2fL88/'  
//启动FileSplitterFetch线程 Tm~#wL +r  
//等待子线程返回 {7pE9R5  
try{ M;RnH##W  
if(bFirst) w_z^5\u0  
{ a,0o{* (u$  
nFileLength = getFileSize(); ?w5nKpG#RI  
if(nFileLength == -1) @R-~zOv  
{ )H37a  
System.err.println("File Length is not known!"); z7l;|T  
} `aWwF} +Y  
else if(nFileLength == -2) 2h? r![  
{ fY\tvo%  
System.err.println("File is not access!"); n]ppO U|[  
} -Bwu$$0  
else )S;Xy`vO  
{ &_%+r5  
for(int i=0;i<nStartPos.length;i++) 4Igs\x{i  
{ @9kk f{?  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 8Jy1=R*S  
} \%4+mgiD  
for(int i=0;i<nEndPos.length-1;i++) :#&U95EC0  
{ T=p}By3a  
nEndPos = nStartPos[i+1]; ~E6+2t*  
} @Qsg.9N3K  
nEndPos[nEndPos.length-1] = nFileLength; &40JN}  
} [Ey%uh 6*  
} &LxzAL,3!  
/ jL{JF>I  
RVKaqJ0e<  
//启动子线程 HI?~t| [y  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; JU%yqXO  
for(int i=0;i<nStartPos.length;i++) 4oa P"T@6  
{ X9`C2fyVd  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ThQEQ6y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +uGP(ONY  
nStartPos,nEndPos,i); #]\G*>{  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);  [;LPeO  
fileSplitterFetch.start(); +fQ$~vr{'  
} ^5@"|m1  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b+j_EA_b  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Nm:<rI,^  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9kg>)ty@  
nEndPos = " + nFileLength); Hr,lA(  
// fileSplitterFetch[nPos.length-1].start(); m=l3O:~J  
C%7)sLWjJS  
]}Hv,a   
//等待子线程结束 ^d $e^cU  
//int count = 0; U &k 3  
//是否结束while循环 Pc ?G^ Xol  
boolean breakWhile = false; F1[ [fH  
3\l9Sf=M|  
]~ 8N  
while(!bStop) <.B > LU  
{ mt]YY<l  
write_nPos(); <W|{)U?p  
Utility.sleep(500); kX .1#%Ex  
breakWhile = true; .;v'oR1x5  
A(sx5Ynp  
<^c0bY1  
for(int i=0;i<nStartPos.length;i++) (2\ekct ^  
{ ..{^"`FQ  
if(!fileSplitterFetch.bDownOver) 5<8>G?Y  
{ LK}eU,m=  
breakWhile = false; :< 3;7R'5  
break; hfa_M[#Q-  
} ?-v?SN#  
} 5:3$VWLa <  
if(breakWhile) NbMH@6%E  
break; =y/ Lbe}:  
mpJ_VS`  
5*'N Q010  
//count++; NW Qu-]P  
//if(count>4) 7Ki7N{K t  
// siteStop(); t7%Bv+Uo  
} D(?#oCCA  
7#*CWh1BNO  
qGUe0(  
System.err.println("文件下载结束!"); APm[)vw#f  
} 0`zq*OQ  
catch(Exception e){e.printStackTrace ();} yAkN2  
} WZ-{K"56  
I}3K,w/7mi  
?Og ;W9i  
//获得文件长度 9e*poG  
public long getFileSize() f3|=T8"t  
{ p tfADG  
int nFileLength = -1; g+F_M  
try{ a m%{M7":7  
URL url = new URL(siteInfoBean.getSSiteURL()); 56aJE .?<  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $)a5;--W  
httpConnection.setRequestProperty("User-Agent","NetFox"); @D{[Hj`<  
y`Y}P1y*  
pMrf i}esx  
int responseCode=httpConnection.getResponseCode(); QCnVZ" !(  
if(responseCode>=400) 82l";;n4p  
{ Mi-9sW  
processErrorCode(responseCode); +& Qqu`)?F  
return -2; //-2 represent access is error @2O\M ,g5  
} 6% axbB  
K?eo)|4)DB  
g 0=t9J  
String sHeader; v65r@)\`  
;:1mv  
ew~FN  
for(int i=1;;i++) :fUmMta  
{ ?7s  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uf3 gVS_h=  
//Utility.log(in.readLine()); ^el:)$  
sHeader=httpConnection.getHeaderFieldKey(i); KwyXM9h6=  
if(sHeader!=null) qA[}\8}h  
{ Jrl xa3 [  
if(sHeader.equals("Content-Length")) _Y~?.hs^  
{ | mX8fRh  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I<#kw)W!  
break; '1*MiFxKq  
} Dne&YVF9V  
} <VPtbM@(m  
else 1yf&ck1R  
break; H[oi? {L  
} ?RyvM_(N6  
} U:(t9NX b  
catch(IOException e){e.printStackTrace ();} ?+_"2XY  
catch(Exception e){e.printStackTrace ();} (ZJ_&8C#  
> [7vX m4  
3EdPKM j&  
Utility.log(nFileLength); N/p_6GYMa  
3M`J.>  
o)DKP>IM#  
return nFileLength; @n3PCH6:Ao  
} BC+qeocg  
IS~oyFS  
^.7xu/T  
//保存下载信息(文件指针位置) u[@*}|uXM  
private void write_nPos() %*hBrjbj  
{ B dUyI_Ks:  
try{ 6<R U~Gh  
output = new DataOutputStream(new FileOutputStream(tmpFile)); X*&r/=  
output.writeInt(nStartPos.length); `^x^= og'  
for(int i=0;i<nStartPos.length;i++) M,P_xkLp  
{ &v88x s  
// output.writeLong(nPos); b1"wQM9  
output.writeLong(fileSplitterFetch.nStartPos); qKXn=J/0tA  
output.writeLong(fileSplitterFetch.nEndPos); 8iB}a\]B  
} e V#H"fM  
output.close(); ^ TS\x/P  
} lRq!|.C  
catch(IOException e){e.printStackTrace ();} vJs /ett  
catch(Exception e){e.printStackTrace ();} 7 #`:m|$  
} O5w\oDhMb  
*{bqHMd4L  
7dRU7p>  
//读取保存的下载信息(文件指针位置) 12E"6E)  
private void read_nPos() }K\_N]#6n  
{ u-$AFSt  
try{ IG\\RYr  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); / e,lD)  
int nCount = input.readInt(); Hqk2W*UTl  
nStartPos = new long[nCount]; Bf.RYLsh6  
nEndPos = new long[nCount]; s Y,3  
for(int i=0;i<nStartPos.length;i++) l;fH5z  
{ 'lF|F+8   
nStartPos = input.readLong(); c4|.!AQ>  
nEndPos = input.readLong(); 6Xa2A 6  
} a &j?"o  
input.close(); R:E:Y|&#  
} (`N/1}vk  
catch(IOException e){e.printStackTrace ();} 9cQSS'`F  
catch(Exception e){e.printStackTrace ();} cW2:D$Pe  
} 3ml|`S  
Q] HRg4r  
@QEV l  
private void processErrorCode(int nErrorCode) @9L9c  
{ _gHJ4(?w  
System.err.println("Error Code : " + nErrorCode); =W6P>r_  
} {+ m)*3~w  
UTz;Sw?~hw  
cjL!$OE6  
//停止文件下载 #'[ f^xgJ  
public void siteStop() %2{E'^#)p-  
{ kF5}S8B  
bStop = true; mMR[(  
for(int i=0;i<nStartPos.length;i++) z t1Q_;  
fileSplitterFetch.splitterStop(); Mm5l>D'c  
*VpQ("  
]PFc8qv{  
} fAK  
} +1Uw<~  
//负责部分文件的抓取 !(]|!F[m  
**FileSplitterFetch.java S'WmPv  
*/ _MR2,mC  
package NetFox; $]vR,E  
{>:2Ff]O:  
J]%P fWV  
import java.io.*; `U1"WcN  
import java.net.*; )gR&Ms4  
0Ec -/   
1Dbe0u  
public class FileSplitterFetch extends Thread { HTC7fS  
I|.B-$gH  
V3-LVgM%  
String sURL; //File URL a'|0e]  
long nStartPos; //File Snippet Start Position k;)L-ge9  
long nEndPos; //File Snippet End Position D -jew&B  
int nThreadID; //Thread's ID ,UP6.C14  
boolean bDownOver = false; //Downing is over R'{V&H^Z  
boolean bStop = false; //Stop identical :+YFO.7  
FileAccessI fileAccessI = null; //File Access interface lfhB2^ ^  
ZE :oK   
?vhW`LXNB  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rScmUt  
{ f7`y*9^  
this.sURL = sURL; ELm#  
this.nStartPos = nStart; N\p3*#M  
this.nEndPos = nEnd; BKIt,7j  
nThreadID = id; W&"FejD  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Mfgd;FsX#  
} ZK;HW  
' ft  |  
h_cZ&P|  
public void run() F2u{Wzr_@  
{ 2@ad! h  
while(nStartPos < nEndPos && !bStop) SZgH0W("L  
{ XW19hG  
<%!@cE+y  
;%U`P8b!  
try{ ^PD a  
URL url = new URL(sURL); 0$UE|yDs>  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z6Mh`:7  
httpConnection.setRequestProperty("User-Agent","NetFox"); 6Us#4 v,  
String sProperty = "bytes="+nStartPos+"-"; ]6%| L  
httpConnection.setRequestProperty("RANGE",sProperty); 3A+d8fwi  
Utility.log(sProperty); `527vK 6  
!6kLg1  
8\[6z0+;  
InputStream input = httpConnection.getInputStream(); &BQ`4j~.  
//logResponseHead(httpConnection); %9M_ * ]  
5r.{vQ  
4WNWn#M  
byte[] b = new byte[1024]; b&!X#3(KT  
int nRead; KQEnC`Nz  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Oh|Hy/&6W  
{ ?&N JN/+%  
nStartPos += fileAccessI.write(b,0,nRead); _xbVAI4  
//if(nThreadID == 1) wc ^z9y  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S3 &L  
} TEY%OI zU+  
M*t{?o/t;  
RhYf+?2  
Utility.log("Thread " + nThreadID + " is over!"); nlJxF5/  
bDownOver = true; Fd3V5h  
//nPos = fileAccessI.write (b,0,nRead); N5 g!,3  
} 0{ \AP<  
catch(Exception e){e.printStackTrace ();} Q|;8\5  
} iLgWzA  
} :sJVklK  
Xbfn@7m  
ab6KK$s  
//打印回应的头信息 c$>Tfa'H  
public void logResponseHead(HttpURLConnection con) h_H$+!Nzb  
{ >d_O0a*W-  
for(int i=1;;i++) aQcJjF5x  
{ AuWEy-q?  
String header=con.getHeaderFieldKey(i); p6|0JBm  
if(header!=null) mI}1si=$  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @<l7"y;\  
Utility.log(header+" : "+con.getHeaderField(header)); uP<tP:  
else ZMoN  
break; q*52|?  
} @<;0 h|  
} O9jqeF`L=  
4R.rSsAH  
FL- sXg  
public void splitterStop() }ufH![|[r  
{ Kk-A?ju@g  
bStop = true; A[^fG_l4  
} *GD?d2.6j  
R{u/r%  
}fdo Aid~  
} L-vy,[9)[*  
)nQA) uz  
j#zUO&Q@  
/* P6@(nGgK<  
**FileAccess.java !Yd7&#s  
*//文件访问(定位,写) !bRoNP  
package NetFox; ?X~Keb  
import java.io.*; 94\k++kc  
?o?~Df&  
\$W>@w0  
public class FileAccessI implements Serializable{ 0escp~\Z  
tWT@%(2~0  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {L4ta~2/T  
RandomAccessFile oSavedFile; $0=f9+@5  
long nPos; N8_ c%6GE  
B^Fe.ty  
1>|2B&_^  
public FileAccessI() throws IOException 5Z@OgR  
{ #Fm,mO$v  
this("",0); \%g# __\  
} t&*X~(Yb!  
-YPUrU[)  
:/A3l=}iV  
public FileAccessI(String sName,long nPos) throws IOException 7&-B6Y4  
{ G&y< lh  
oSavedFile = new RandomAccessFile(sName,"rw"); D% v{[ KY  
this.nPos = nPos; krnxM7y  
oSavedFile.seek(nPos); "Y-_83  
} f_I6g uDPz  
!#xk?LyB  
[Wf%iwB  
public synchronized int write(byte[] b,int nStart,int nLen) s"gNHp.oF  
{ 1 CXO=Q  
int n = -1; *.qm+#8W  
try{ }V:ZGP#!'  
oSavedFile.write(b,nStart,nLen); > PHin%#  
n = nLen; C+tB$yahO  
} RE 6d&#N  
catch(IOException e) ]6#bp,  
{ HtFc+%=  
e.printStackTrace (); wA$ JDf)Vg  
} jJc:%h$|2  
sbqAjm}  
KsVN<eR{  
return n; J'4Pp<  
} p(vmMWR!  
WOkAma-  
O1xK\ogv  
} _ x8gEK8  
2nz^%pLT  
"=H(\ V  
/* tr?U/YG  
**SiteInfoBean.java x6N)T4J(  
*/ *,az`U  
package NetFox; z'"e|)  
Es]:-TR  
!:BmDX[<n  
public class SiteInfoBean { bSJ@ 5qS  
'/O >#1  
^W#161&  
private String sSiteURL; //Site's URL Z/G`8|A  
private String sFilePath; //Saved File's Path 8=kIN-l_  
private String sFileName; //Saved File's Name #X 1 GL  
private int nSplitter; //Count of Splited Downloading File X?f\j"v  
\P~ h0zg?  
\%BII>VS  
public SiteInfoBean() R^*%yjy9  
{//nSplitter的缺省值为5 dBRK6hFC  
//default value of nSplitter is 5 j{&*]QTN  
this("","","",5); >>nOS]UL  
} e)BU6m%  
fmgXh)=  
CqFk(Td9-D  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^]n:/kZ5"[  
{ H"5=z7w  
sSiteURL= sURL;  2-$O$&s.  
sFilePath = sPath; X^o0t^  
sFileName = sName; 1Y+g^Z;G  
this.nSplitter = nSpiltter; U,Q  
IEmjWw4  
0#y i5U  
} &) qs0  
6Cj$x.-K  
(baBi9<P=  
public String getSSiteURL() [%LIW%t|  
{ X:2)C-l?  
return sSiteURL; M4}b l h#  
} Wd>gOE  
nVyV]'-z  
1[:tiTG|C  
public void setSSiteURL(String value) Bcl6n@{2f  
{ r7FFZNs!  
sSiteURL = value; ^!A@:}t>  
} A<p6]#t#X)  
&"6%D|Z0  
uz;zmK  
public String getSFilePath() HRg< f= oz  
{ XMlcY;W  
return sFilePath; Vw";< <0HZ  
} |V-)3 #c  
eKvQS}11  
Qv B%X)J  
public void setSFilePath(String value) Lq#$q>!K  
{ )(V!& w6  
sFilePath = value; \AY*x=PF  
} #-7w |  
UPcx xtC  
{?uG] G7  
public String getSFileName() x5(B(V@b  
{ w%?6s3   
return sFileName; ]I: h4hgw  
} |R3A$r#-  
M _e^KF  
!n3J6%b9y/  
public void setSFileName(String value) FA$1&Fu3Y  
{ (5h+b_eB  
sFileName = value; fI }v}L^  
} l<-0@(x)  
~]78R!HJ  
OM (D@up  
public int getNSplitter() lG R6S  
{ Yq0jw&v  
return nSplitter; i1 ^#TC$x  
} T{4Ru6[  
?TMrnR/d  
#xNXCBl]O  
public void setNSplitter(int nCount) nO;t5d  
{ l'FNp  
nSplitter = nCount; EF8'ycJk+  
} ZnZ`/zNO  
} xB|?}uS-  
RGz NZc  
hM[QR'\QS  
/* ;S}_/'  
**Utility.java f[+N=vr  
*/ Q}|QgN  
package NetFox; (4"Azo*~![  
dFzlcKFFD  
M&ec%<lM  
public class Utility { ]#P>wW  
Q|Go7MQZ@k  
<~iA{sY)O  
public Utility() 'w`3( ':=  
{ &k@r23V7r  
|yYu!+U  
2>h.K/pC  
} lQl  
p?Jx2(%m  
//线程睡眠 |n*<H|  
public static void sleep(int nSecond) j7v?NY  
{ ZE4xF8  
try{ $94l('B6H  
Thread.sleep(nSecond); ZuVes?&j  
} 3-U@==:T  
catch(Exception e) ST25RJC  
{ "FH03 9  
e.printStackTrace (); yGX"1Fb?;x  
} Pj7n_&*/  
} a6epew!2  
+kZW:t!-  
//日志  HV\l86}  
public static void log(String sMsg) 9xM7X?  
{ /8"9 sf *  
System.err.println(sMsg); NTy0NH  
} |^T?5=&Kt  
y)D7!s  
AA~6r[*~  
public static void log(int sMsg) 5~E'21hJ  
{ B<6Ye9zuG  
System.err.println(sMsg); \zv?r :1t  
} d!#qBn$*[  
} THf*<|  
+9[s(E?SY  
q<>aZ|r  
/* ht5eb"c+ 8  
**TestMethod.java tp?< e  
*/ `AcT}. u  
package NetFox; 2-x#|9  
0pl |  
sEm064  
public class TestMethod { yVl?gGgh  
_|} GhdYE  
J)"g`)\2+  
public TestMethod() 7^*[ XH  
{ ///xx/weblogic60b2_win.exe x/^,{RrPk  
try{ 61=D&lb  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /G& %T  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^Uq"hT(41  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,/6 aA7(  
fileFetch.start(); F2Nb]f  
} Y!nxHRE  
catch(Exception e){e.printStackTrace ();} @WfX{485  
w;4FN'  
\'.#of  
} NZ=`iA8)X  
P/;d|M(  
y;1l].L  
public static void main(String[] args) 8e*1L:oB!  
{ h4lrt  
new TestMethod(); ZA Xw=O5  
} /R!/)sg  
} 3 F ke#t  
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