http断点续传简单实现（java)

/* 8493Sw  
**SiteFileFetch.java |-S!)iG1V  
*/ U'" #jT  
package NetFox; &K'*67h  
import java.io.*; GBB
r[}y-  
import java.net.*; xOShO"4Z   
d6t
v4Cf  
DQW)^j h  
public class SiteFileFetch extends Thread { !^F_7u@Q  
-n|>U:  
L)U*dY  
SiteInfoBean siteInfoBean = null; //文件信息Bean _p:n\9k  
long[] nStartPos; //开始位置 4bL *7
bA  
long[] nEndPos; //结束位置 Ve"(}z  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 %b*N.v1+  
long nFileLength; //文件长度 n^{h@u  
boolean bFirst = true; //是否第一次取文件 d*Mqs}8  
boolean bStop = false; //停止标志 Yu" Q  
File tmpFile; //文件下载的临时信息 (SW6?5  
DataOutputStream output; //输出到文件的输出流 /Q7q2Ne^*  
Hm'fK$y(  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） J2x}@p  
public SiteFileFetch(SiteInfoBean bean) throws IOException n7;jME/!  
{ D%3$"4M7!  
siteInfoBean = bean; @R`6jS_gK  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ?+d{Rh)y  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); lFtEQ '}  
if(tmpFile.exists ()) R3og]=uFzm  
{ b1#C,UWK  
bFirst = false; s|XWw<Sa  
read_nPos(); S[$9_Jf  
} xva e^gr  
else EmO[-W|2  
{ dDl+  
nStartPos = new long[bean.getNSplitter()]; R2~y<^.V`Y  
nEndPos = new long[bean.getNSplitter()]; %>+lr%B  
} '"7b;%EN'  
c3l(,5DtH  
&uE )Vr4R  
FEu}zt@  
} ,_(=w.F   
\,/ozfJ7dT  
jEQ_#KKYJ  
public void run() (Q||
5  
{ =/'>.p3/S  
//获得文件长度 .?g=mh79(  
//分割文件 @BnK C&{  
//实例FileSplitterFetch m[y~-n  
//启动FileSplitterFetch线程 [>GblL  
//等待子线程返回 Ji,;ri2
i  
try{ }*9F`=%F  
if(bFirst) mIG>`7`7N  
{ |*J;X<Vm  
nFileLength = getFileSize(); xzY/$?  
if(nFileLength == -1) }03?eWk/y  
{ y~]D402Cx  
System.err.println("File Length is not known!"); R&t2   
} c%,ky$'18  
else if(nFileLength == -2) y'2w*?  
{ @6DKw;Q  
System.err.println("File is not access!"); r%=a:GdAg  
} EmUt/]  
else 2Q(ZW@0  
{ @(=?x:j  
for(int i=0;i<nStartPos.length;i++) -6_<]  
{ *wqR.n?  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); g$)0E<  
} r`FTiPD.C  
for(int i=0;i<nEndPos.length-1;i++) 3nh
Q^zqf  
{ rLD1Cpeb,w  
nEndPos = nStartPos[i+1]; ) xV>Va8)  
} hA/Es?U]  
nEndPos[nEndPos.length-1] = nFileLength; -u~:Gd*l0  
} 4?(=?0/[  
} S]fkA6v  
?T%"Jgy8  
Su,<idS  
//启动子线程 Z[z" v  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !T)_(}|6}  
for(int i=0;i<nStartPos.length;i++) !7]^QdBLY  
{ 2|exY>`w  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 23=wz%tF  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \C;Yn6PK0  
nStartPos,nEndPos,i); [=.iJ5,{2  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `3K."/N6c  
fileSplitterFetch.start(); 4M>]0%3.D  
} ~9!@BL\  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P&c O2  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :&$v.#  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", BB1_EdoG  
nEndPos = " + nFileLength); <|WXFjn  
// fileSplitterFetch[nPos.length-1].start(); S9b=?? M)  
th"Aatmp  
kJ.7C  
//等待子线程结束 3,#qt}8`  
//int count = 0; CIwI1VR^  
//是否结束while循环 J+Y?'"r  
boolean breakWhile = false; Wa?\W&  
xw~oR|`U  
Ttb?x<)+8  
while(!bStop) ow,! 7|m  
{ Y?oeP^V'u  
write_nPos(); N-p||u  
Utility.sleep(500); 0"sZP\<p  
breakWhile = true; L)H/t6}i  
"0>AefFd#  
{c $8?6  
for(int i=0;i<nStartPos.length;i++) r5lPO*?Df  
{ M6Ik'r"M  
if(!fileSplitterFetch.bDownOver) z+_d*\  
{ [4])\q^q  
breakWhile = false; lH,/N4r*&  
break; K[V#Pj9  
} oC!z
+<  
} HXB& 6  
if(breakWhile) /I`-  
break; k_OzkEM9!  
`- 9p)@'8k  
sw(|EZ7F  
//count++; ,}^;q58  
//if(count>4) |t58n{V.O  
// siteStop(); tg2+Z\0)4g  
} `Z@qWB<  
1R.6Xer  
>ISBK[=H  
System.err.println("文件下载结束！"); y&F&Z3t  
} UQT=URS  
catch(Exception e){e.printStackTrace ();} \VAS<?3  
} k#5Qwxu`  
z_$F)*PL  
3qp\jh=FE  
//获得文件长度 jpiBHi]5+  
public long getFileSize() SUoUXh^!w  
{ ^"J)^3j<  
int nFileLength = -1; al]-*=v7}  
try{ QIcc@PGT9a  
URL url = new URL(siteInfoBean.getSSiteURL()); 0*/[z
~Z-1  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7t% |s!~  
httpConnection.setRequestProperty("User-Agent","NetFox"); ~N+H7T.L  
b5
%T)hn=  
Xf|I=XK  
int responseCode=httpConnection.getResponseCode(); eC$
Jdf  
if(responseCode>=400)
KD..X~Me  
{ mx0EE
U*  
processErrorCode(responseCode); &
UX:KW`=  
return -2; //-2 represent access is error W
Sx0o}  
} KN\tRE  
JHsxaX;c  
e6'y S81  
String sHeader; OGnuBK
 
YGCBDH%6  
P?`
a{sl.  
for(int i=1;;i++) U{&gV~  
{ pb|,rLNZ  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J@(69&  
//Utility.log(in.readLine()); u_%L~1+'  
sHeader=httpConnection.getHeaderFieldKey(i); 1xb1?/n1#  
if(sHeader!=null) y-a
3  
{ ^[hx`Rh`t  
if(sHeader.equals("Content-Length")) KyRcZ"  
{ <3[0A;W=1  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &]1gx#  
break; M:.0]'[s5  
} pn aSOyR  
} @`:z$52  
else j4]y(AA  
break; Qis/'9a  
} bm-&H  
} @*5(KIeeC>  
catch(IOException e){e.printStackTrace ();} '"]U+aIg  
catch(Exception e){e.printStackTrace ();} =$F<Ac;&  
,^&amWey  
KWiP`h8  
Utility.log(nFileLength); }9 I,p$  
*w23(f  
=]W[{@P  
return nFileLength;
$3^Cp_p6  
} cP>[H:\Xc  
nm]m!.$d  
7Nlk:f)*-  
//保存下载信息（文件指针位置） }o@Dsx5  
private void write_nPos() ow K)]t  
{ j4}Q  
try{ rE9Nt9}  
output = new DataOutputStream(new FileOutputStream(tmpFile)); L_R(K89w  
output.writeInt(nStartPos.length); M.fA5r
J^  
for(int i=0;i<nStartPos.length;i++) -$cO0RSY  
{ i&\cDQ 3  
// output.writeLong(nPos); O#x=iZI  
output.writeLong(fileSplitterFetch.nStartPos); -s9()K(vZG  
output.writeLong(fileSplitterFetch.nEndPos); Jqz K5)  
} t-)d*|2n}o  
output.close(); &r1]A&  
} dnCurWjdk  
catch(IOException e){e.printStackTrace ();} B PG&R  
catch(Exception e){e.printStackTrace ();} z^\-x9vL  
} @k-iy-|3)  
w7b\?]}@  
ZMO ym=  
//读取保存的下载信息（文件指针位置） FPukV^  
private void read_nPos() W7"UhM  
{ u
Fn?U)  
try{ ~
;ObT=  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J(w 3A)(  
int nCount = input.readInt(); (ty&$  
nStartPos = new long[nCount]; qpV"ii  
nEndPos = new long[nCount]; [Z;ei1l  
for(int i=0;i<nStartPos.length;i++) MM(\>J[Uq  
{ jR
>`Xz  
nStartPos = input.readLong(); d8K|uEHVz  
nEndPos = input.readLong();
1C(sBU"  
} %BF,;(P  
input.close(); -lm)xpp1  
} $0|`h)&  
catch(IOException e){e.printStackTrace ();} bL/DjsZ@  
catch(Exception e){e.printStackTrace ();} C!)ZRuRv  
} H:cAORLB  
=:'\wx X  
__}ut+H^5p  
private void processErrorCode(int nErrorCode) (@V_47o  
{ 2@Oz_?O=  
System.err.println("Error Code : " + nErrorCode); *U +<Hv`C  
} z0@BBXQ`  
ic}mru  
a9NIK/9  
//停止文件下载 iw%""q(`  
public void siteStop() ZmmX_!M  
{ w@pJ49  
bStop = true; "r1 !hfIYf  
for(int i=0;i<nStartPos.length;i++) 2"_5Yyb  
fileSplitterFetch.splitterStop(); )YW"Zo8~!1  
$$i Gs6az  
~BMUea(  
} wHh6y?g\  
} U9jdb9 |  
//负责部分文件的抓取 -kHJH><j  
**FileSplitterFetch.java 88l1g,`**  
*/ aJ}hlM>  
package NetFox; X8):R
- J  
*Qyu QF  
H!'4A&  
import java.io.*; kW0ctGFYlf  
import java.net.*; ZG-#YF.1  
Xk\IO0GF  
z/fSstN  
public class FileSplitterFetch extends Thread { q;*'V9#  
%7QSBL  
&hrMpD6z6i  
String sURL; //File URL rgDl%X2B  
long nStartPos; //File Snippet Start Position [w!
T  
long nEndPos; //File Snippet End Position
suE8"v!sk  
int nThreadID; //Thread's ID bg|dV  
boolean bDownOver = false; //Downing is over Uz~B`  
boolean bStop = false; //Stop identical {{?MO{Mh*  
FileAccessI fileAccessI = null; //File Access interface T?RN} @D  
 $@O?  
%!eRR  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fefy`J  
{ ~f"3Wa*\B  
this.sURL = sURL; r+h%a~A#>  
this.nStartPos = nStart; iJj!-a:z.  
this.nEndPos = nEnd; EIfqRRTA  
nThreadID = id; }zxf~41  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P(DEf(  
} Bex;!1  
8:)[.  
Ghc U~  
public void run() Ijap%l1I  
{ RyU8{-q  
while(nStartPos < nEndPos && !bStop) *JfGGI_E  
{ ` &bF@$((  
[VqiF~o,  
\F-n}Z  
try{ ]uF7HX7
F  
URL url = new URL(sURL); x2a ?ugQ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8EMBqhl  
httpConnection.setRequestProperty("User-Agent","NetFox"); cJbv,RV<  
String sProperty = "bytes="+nStartPos+"-"; !L|l(<C  
httpConnection.setRequestProperty("RANGE",sProperty); M$.bC0}T  
Utility.log(sProperty); F(zCvT   
kZo#Ny  
Ph%ylS/T{  
InputStream input = httpConnection.getInputStream(); 6rj iZ%  
//logResponseHead(httpConnection); 6"Lyv  
\At~94  
#d3_7rI0V  
byte[] b = new byte[1024]; Fx}v.A5  
int nRead; .P7q)lj36h  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .>}I/+n  
{ Y0kcxpK/  
nStartPos += fileAccessI.write(b,0,nRead); 2O@ON/  
//if(nThreadID == 1) s8[(   
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X Db%-  
} 7Ok-T10  
QIU%!9Y  
SP<Sv8Okj  
Utility.log("Thread " + nThreadID + " is over!"); j>?nL~{  
bDownOver = true; =OtW!vx#R.  
//nPos = fileAccessI.write (b,0,nRead); p7Zeudmj  
} 5de1rB|  
catch(Exception e){e.printStackTrace ();} eY`9J4o'  
} A^6z.MdYZ  
} l3BN,HNv+  
"%+||IyW  
D</?|;J#/  
//打印回应的头信息 X]2Ib'(  
public void logResponseHead(HttpURLConnection con) 2]Cn<zJ  
{ x=a#|]ngG  
for(int i=1;;i++) l l*g *zt3  
{ *0@Z+'M?  
String header=con.getHeaderFieldKey(i); rA8NE>  
if(header!=null) EXj
R&"R  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %%n&z6w-  
Utility.log(header+" : "+con.getHeaderField(header)); ^`dMjeF  
else z1,#ma}.  
break; f%t N2k  
} p=eSJ*  
} S{bp'9]$y  
7Dl^5q.|  
i !sVQ(:  
public void splitterStop() <_pLmYI  
{ n} !')r  
bStop = true; z=>PjIW  
} >wb*kyO7(#  
_X<V`, p  
Sh-B!  
} ]Hi1^Y<  
zK1\InP  
~Ni-}p  
/* ASMItT  
**FileAccess.java ZJGIib  
*//文件访问(定位，写) %jq R^F:J  
package NetFox; X2| Z!  
import java.io.*; #z.\
pd  
<?8cVLW}O  
wod{C!  
public class FileAccessI implements Serializable{ yJqDB$0  
F/p1?1M  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FU}- .Ki  
RandomAccessFile oSavedFile; ]k1
N-/  
long nPos; "Ya;
&F.'  
Cx(HsJ!,  
"].TKF#yg  
public FileAccessI() throws IOException c(?OE' "Z  
{ rSW{1o'  
this("",0); WwSyw?T  
} D,-L!P  
biffBC:q  
uSCI  
public FileAccessI(String sName,long nPos) throws IOException flBJO.2  
{ ,<OS:]  
oSavedFile = new RandomAccessFile(sName,"rw"); FuBUg _h  
this.nPos = nPos; Dn~t_n  
oSavedFile.seek(nPos); ;lTgihW-  
} *;t_VlaZ  
,0>_(5  
S|@ Y !  
public synchronized int write(byte[] b,int nStart,int nLen) `wLmGv+V  
{ Hpp;dG  
int n = -1; _1$+S0G;  
try{ JvW!w)$pY  
oSavedFile.write(b,nStart,nLen); AucX4J<  
n = nLen; 6XVJ/q
Z  
} DshRH>7s8  
catch(IOException e) 5M3)7  
{ *nUa0Zg4q6  
e.printStackTrace (); }T=\hM  
} FFF7f5F  
R*O6Z"h  
P'Jb')m  
return n; =OA7$z[  
} mO\=#Q>  
gD6BPW~0  
ve=1y)  
} @eDL j}  
rk?G[C)2c  
><;.vP
 
/* &\r_g!Mh  
**SiteInfoBean.java qSL~A-  
*/ RAEiIf!3  
package NetFox; Tj=g[)+K  
*_yp]z"  
3+%L[fW`/  
public class SiteInfoBean { VoUAFEcs  
]p~,C*UH0  
JvLa@E)  
private String sSiteURL; //Site's URL r\{; ~V  
private String sFilePath; //Saved File's Path en gh3TZC  
private String sFileName; //Saved File's Name 4T#Z[B[  
private int nSplitter; //Count of Splited Downloading File nr{}yQu  
8,
(5Q  
3gmu-tv  
public SiteInfoBean() o"A%dC_  
{//nSplitter的缺省值为5 V|dKKb[Lve  
//default value of nSplitter is 5 uI[lrMQYa  
this("","","",5); K<tkNWasQ  
} t)~v5vr  
C0Ti9  
%"RgW\s[R  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C{):jH,Rf  
{ lV!@h}mG  
sSiteURL= sURL; re}P  
sFilePath = sPath; E%+1^ L  
sFileName = sName; I"+;L4o`  
this.nSplitter = nSpiltter; BI6o@d;=4  
Ow]c,F}^  
TXQY&7  
} "%Eyb\V!  
3AD^B\<gB  
#S4{,  
public String getSSiteURL() PDssEb7  
{ A5gdZZ'x  
return sSiteURL; Iih~rWJ  
} "VcG3.  
R:v`\  
`795K8  
public void setSSiteURL(String value) -3c?Yaf"  
{ T=2 91)@  
sSiteURL = value; =jmn  
} rm4j8~Ef  
2FS,B\d  
R('44v5JQp  
public String getSFilePath()  B9^@]  
{ C@L:m1fz  
return sFilePath; T{j&w%(z  
} X Jy]d/  
7
@Qz  
9oY%v7  
public void setSFilePath(String value) ?ei7jM",  
{ Ydu=Jg5u7  
sFilePath = value; DP*[t8  
} PhM3?$  
C;;dCsiV5  
cX553&  
public String getSFileName() z@biX  
{ BaTE59W  
return sFileName; /W/ =OPe  
} %Ow,.+m  
0=&Hm).  
ueYZM<],  
public void setSFileName(String value) Ssr P  
{ m^Btr  
sFileName = value; fXBA P10#  
} t8 #&bUX  
h4S,(*V$!  
X%S?o  
public int getNSplitter() HkEfBQmh  
{ D'#Wc#b  
return nSplitter; pl V]hu27K  
} =g$%.  
B9n$8QS  
W)?B{\  
public void setNSplitter(int nCount) 7 rOziKZ"  
{ +PY LKyS>  
nSplitter = nCount; Lu6!W  
} < ppg$;  
} soXeHjNl  
sC48o'8(  
/A4zR  
/* @%fNB,H`
 
**Utility.java frk(2C8T  
*/ iXMs*GcK  
package NetFox; KE`}P<K&  
kf>oZ*/  
hkee,PiiP  
public class Utility { $3|++?  
|#Bz&T  
hdp;/Qz&  
public Utility() ogH{   
{ Oj6-  
kcVEE)zb  
gh|TlvnA  
} aRdzXq#x  
DZ |0CB~  
//线程睡眠 x-,+skZs  
public static void sleep(int nSecond) iVLfAN @  
{ #TM+Vd$  
try{ J1T_wA_  
Thread.sleep(nSecond); &xo,49`!  
} +Fp8cT=1  
catch(Exception e) V<Q''%k  
{ ;"$Wfy  
e.printStackTrace ();
V)72]p  
} 4R0'$Ld4  
} fwK5p?Xhm  
8e:J{EG~  
//日志 //n$#c_}u  
public static void log(String sMsg) I{U7BZy  
{ _8Cw_  
System.err.println(sMsg); ;fw}<M!6  
} ZgK[,<2  
U1}-]^\  
j\iE3:94$  
public static void log(int sMsg) @&p:J0hbp  
{ 1t wC-rC  
System.err.println(sMsg); 3DRJl,v  
} L&ucTc=  
} jR[VPm=  
n@xC?D:t*  
Is1P,`*!  
/* viB'ul7o  
**TestMethod.java !Hq$7j_  
*/ m:&go2Y  
package NetFox; KT$Za
  
@yp#k
>  
fUj[E0yOF  
public class TestMethod { *?bOH5$@Nw  
]!CMo+  
]Fi_v?42x  
public TestMethod() C.qNBl*  
{ ///xx/weblogic60b2_win.exe 'u@,,FFz[K  
try{ m31l[e  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lTb4quf8I  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jN))|eD0x  
SiteFileFetch fileFetch = new SiteFileFetch(bean); skrdL.5  
fileFetch.start(); Z~
R7 G  
} ?APzb4f^W  
catch(Exception e){e.printStackTrace ();} CjR!dh1w_  
gOiZ8K!  
3dO~Na`S  
} zF: :?L~  
x[u4>f  
p>#sR4d>  
public static void main(String[] args) F*u"LTH  
{ }2xgm9j<  
new TestMethod(); +
O$`8a)m  
} 2P35#QI[)  
}  4,g_$)  
点击下载更多相关资料