http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); |D'!.$7%
} #t# S(A9)
for(int i=0;i<nEndPos.length-1;i++) l.}gWN9-
{ q9^.f9-
nEndPos = nStartPos[i+1]; _m#TL60m
} b-c6.aKf|
nEndPos[nEndPos.length-1] = nFileLength; .OW5R*
} >: @\SU
} Fghan.F
>E,/|K*
|VM=:}s&
//启动子线程 xw1,Wbu]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K_N`My
for(int i=0;i<nStartPos.length;i++) t[b(erO'
{ yM-%x1r~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0r&FH$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DuQ:82 3b
nStartPos,nEndPos,i); \IR$~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3] U/^f3
fileSplitterFetch.start(); $K|2k7
} jM'Fb.>~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "JYWsE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3VQmo\li
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", dsK^-e6:5
nEndPos = " + nFileLength); Z\)P|#L$
// fileSplitterFetch[nPos.length-1].start(); D9r;Ys%
oJ=u pnBn-
c8cGIAOY)
//等待子线程结束 p1ER<_fp
//int count = 0; )B5U0iIi
//是否结束while循环 bG)6p05Oa
boolean breakWhile = false; _xP@kN~
:{xu_"nYr
h{E9rc1,
while(!bStop) z7*mT}Q
{ vZSwX@0
write_nPos(); &v r0{]V^
Utility.sleep(500); ljh,%#95=
breakWhile = true; &#]||T-
mx^rw*'JGC
lWU? R
for(int i=0;i<nStartPos.length;i++) %U97{y
{ ^DR`!.ttr
if(!fileSplitterFetch.bDownOver) OadGwa\:s
{ &gvX<X4e
breakWhile = false; LFQPysC
break; n]wZ7z
} Vao3&#D8
} 8GT{vW9
if(breakWhile) VDv>I 2%
break; YW-Ge
DTx>^<Tk
lN::veD
//count++; p:|p?
//if(count>4) [-Mfgw]i
// siteStop(); qIgb;=V
} mY]R~:
t*!Q9GC_
bd.t|A
System.err.println("文件下载结束！"); x$V[xX
} MqswYK-s
catch(Exception e){e.printStackTrace ();} If.hA}
} gMZ `
-M?s<R[&
locf6%2g~
//获得文件长度 ).>O6A4:C
public long getFileSize() k%ckV`y
{ lV<j?I~?Q
int nFileLength = -1; *ps")?tlC
try{ ob>2SU[Y
URL url = new URL(siteInfoBean.getSSiteURL()); c ]&|.~2&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Tk0Senq,
httpConnection.setRequestProperty("User-Agent","NetFox"); {= l9{K`~
cH\.-5NQ
k7Xa|&fQP<
int responseCode=httpConnection.getResponseCode(); IqmoWn3
if(responseCode>=400) FDO$(&
{ Y+#VzIZw
processErrorCode(responseCode); :+\B|*T2.L
return -2; //-2 represent access is error GbZqLZ0
} skn];%[v\
FOd)zU*L2
Ny)!uqul*
String sHeader; veh?oJi@
2q.J1:lW
6N'v`p8
for(int i=1;;i++) '\.fG\xD
{ ~!a~ -:#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^iaG>rvA
//Utility.log(in.readLine()); ^<O=<tN\
sHeader=httpConnection.getHeaderFieldKey(i); pElAY3
if(sHeader!=null) Y5Jrkr)k
{ v9s/!<j
if(sHeader.equals("Content-Length")) k~ZE4^dM
{ li?RymlF
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p$ %D
break; #Y;_W;#
} z<c@<M=Q*
} =tE7XC3X_
else !B &%!06
break; *^q%b/f
} }?jL;CCe
} xr*hmp1
catch(IOException e){e.printStackTrace ();} 'XHKhpm<
catch(Exception e){e.printStackTrace ();} ki[Yu+';}
WS?"OTH.^\
?tLBEoUmKT
Utility.log(nFileLength); -_RMiGM?T
jKI0d+U
5g3D}F>OJ
return nFileLength; G'sEbw'[
} gE>_:s
b+.P4+
nDvj*lZF
//保存下载信息（文件指针位置） tGcp48R-:+
private void write_nPos() bZ.q?Hlfk
{ ,dM}B-
try{ O%.c%)4Xo
output = new DataOutputStream(new FileOutputStream(tmpFile)); G92Ya^`
output.writeInt(nStartPos.length); ? LA>5
for(int i=0;i<nStartPos.length;i++) <V-D
{ Q$NT>d6Q
// output.writeLong(nPos); rG _T!']~
output.writeLong(fileSplitterFetch.nStartPos); l H@hV
output.writeLong(fileSplitterFetch.nEndPos); cZ{-h
} #R<ErX)F
output.close(); 0Y8Si^T
} 1d4?+[)gUv
catch(IOException e){e.printStackTrace ();} o+o'!)
catch(Exception e){e.printStackTrace ();} `J%iFm/5*
} c5& _'&
tiI:yq0
s3sAw~++
//读取保存的下载信息（文件指针位置） IXaF(2>
private void read_nPos() >8$]g
{ l0^~0xlED
try{ tCFXb6Cz
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); iB =R
int nCount = input.readInt(); =}6yMR!4R<
nStartPos = new long[nCount]; %z}{jqD&:X
nEndPos = new long[nCount]; /T53"+7:0
for(int i=0;i<nStartPos.length;i++) U8+5{,$\.
{ UQmdm$.
nStartPos = input.readLong(); )*=ds,
nEndPos = input.readLong(); "Zo<$p3]
} WJp9io[GM
input.close(); Z=P]UD
} n2NxO0
catch(IOException e){e.printStackTrace ();} ev}lb+pr)_
catch(Exception e){e.printStackTrace ();} }IM*Vsk
} aNX M~;5~
8[zux4<m
.DzFtc
private void processErrorCode(int nErrorCode) ?pS,?>J f
{ PyOj{WX>W
System.err.println("Error Code : " + nErrorCode); g%P6f
} j06q3N"
+HGPn0As
3ZZ"mlk*
//停止文件下载 hRU.^Fn#%
public void siteStop() I\%a<
{ bqmb|mD
bStop = true; ;7jszs.6%
for(int i=0;i<nStartPos.length;i++) Pz+2(Z
fileSplitterFetch.splitterStop(); `Bw>0%.
Ev adY
7+!4pf
} (#uz_/xXa
} =UGyZV:z5
//负责部分文件的抓取 !'y9/
**FileSplitterFetch.java !^~ ^D<
*/ p_^Jr*Mv
package NetFox; TuF;>{~}
g4Y1*`}2f
P2U^%_~
import java.io.*; %rU8^'Gu
import java.net.*; xL-]gwq
ZDQc_{e{
<'{*6f@n
public class FileSplitterFetch extends Thread { F$tshe(
Pdq}~um3{
|z1
String sURL; //File URL )=~OP>7B
long nStartPos; //File Snippet Start Position [&Yrnkgr
long nEndPos; //File Snippet End Position z(00"ei
int nThreadID; //Thread's ID |`N|S
boolean bDownOver = false; //Downing is over 2=\} 0
boolean bStop = false; //Stop identical 8h,>f#)0c
FileAccessI fileAccessI = null; //File Access interface })?t:zX#*
`#/0q*$
HLlp+;CF><
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException No|T#=BZ[
{ U*p;N,SjQ
this.sURL = sURL; r]sNI[
this.nStartPos = nStart; e-Pn,j
this.nEndPos = nEnd; mz[Q]e~&i
nThreadID = id; F,[GdE;P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4qsP/`8
} vYPZVqF_$
-Lo3@:2i
Em<B9S
public void run() Whd\Ub8(
{ JZl"k
while(nStartPos < nEndPos && !bStop) #YiphR&
{ j[ fE^&
w \U?64
(C3:_cM5
try{ ~W>3EJghR,
URL url = new URL(sURL); {^z>uRZ3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eBZ94rA]
httpConnection.setRequestProperty("User-Agent","NetFox"); `X8wnD
String sProperty = "bytes="+nStartPos+"-"; (XU(e
httpConnection.setRequestProperty("RANGE",sProperty); rk E;OU
Utility.log(sProperty); nT:F{2 M;
?LwBF;Y
_9pcHhJux
InputStream input = httpConnection.getInputStream(); at )m*
//logResponseHead(httpConnection); X21k7 Ls
3FglzJ
wni^qs.i@3
byte[] b = new byte[1024]; fe3a_gYPz
int nRead; !*\J4bJe
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u6t%*''
{ S^q%+Z
nStartPos += fileAccessI.write(b,0,nRead); Ux!q(9<_
//if(nThreadID == 1) ;"9$LHH*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d5YL=o
} F*Y]^9]
l:.q1UV
*-vH64e
Utility.log("Thread " + nThreadID + " is over!"); =mp"=%
bDownOver = true; =^5#o)~BB
//nPos = fileAccessI.write (b,0,nRead); P-_2IZiz
} ]=%oBxWAP
catch(Exception e){e.printStackTrace ();} Y(<(!TJ-
} 7%sx["%@
} kZK1{
)4;$;a1
2)\gIMt%
//打印回应的头信息 L2Z-seE
public void logResponseHead(HttpURLConnection con) bCg)PJuB
{ aJzyEb
for(int i=1;;i++) +=Y$v2BZA3
{ :m[HUh
String header=con.getHeaderFieldKey(i); !<UdG+iV
if(header!=null) *G"}m/j-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G@4n]c_
Utility.log(header+" : "+con.getHeaderField(header)); BmI'XB3'P
else er0y~
break; 68()2v4X
} iI$;%uY3g
} h @2.D|c)g
FwpTQix!
lhBu?q
public void splitterStop() bNG7A[|B
{ 5,#aN}v#?
bStop = true; p1']+4r%
} C5^9D
_X~xfmU
ZRP[N)Ld$
} n%d7`?tm4
,aU8. J_U
T( CTU/a-,
/* Jl fIYf~
**FileAccess.java )5ev4Qf
*//文件访问(定位，写) :OD-L)Or
package NetFox; axM(3k.n
import java.io.*; |o#pd\
m/"}Y]n!
/&o<kY
public class FileAccessI implements Serializable{ T1A/>\Ns
gCZm7dgo
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,H@ x.
RandomAccessFile oSavedFile; nyx(0
long nPos; Og:aflS
E.4 X,
\^Z DH
public FileAccessI() throws IOException "q7pkxEuJ
{ ?Vc/mO2X
this("",0); MmW]U24s
} Kj6@=
xeKfc}:&z
7D=gAMPvJ
public FileAccessI(String sName,long nPos) throws IOException "[2D&\$
{ zxy/V^mu
oSavedFile = new RandomAccessFile(sName,"rw"); ,H5o/qNU`{
this.nPos = nPos; 8RJa;JsH
oSavedFile.seek(nPos); jWGX:XB
} o(Q='kK
~?:Xi_3Lo
dRXdV7-!
public synchronized int write(byte[] b,int nStart,int nLen) 1V;m8)RF
{ m8z414o
int n = -1; WbHI>tt
try{ Z]k+dJ[-
oSavedFile.write(b,nStart,nLen); Q_FL8w9D~8
n = nLen; .!Q?TSQ+{!
} {3N5Fi7S
catch(IOException e) skBzwVW I
{ b-)3MR:4
e.printStackTrace (); j?s+#t
} =>Dw,+"
ez^b{s`
Qh,Dcg2ZM"
return n; <j^"=UN4#
} \j~LxV
Yf[GpSej
X{;3gN
} 42 &m)
-LMO f[v?
KGsW*G4U=
/* H^0`YQJ3
**SiteInfoBean.java & <Jvaf_=
*/ =y1/V'2E
package NetFox; ?G$X 4KY6`
qh~S)^zFJ
.="[In'
public class SiteInfoBean { MDh^ic5
=]hPX
jthGNVZ
private String sSiteURL; //Site's URL A]mXV4RmI
private String sFilePath; //Saved File's Path 2ZZF hj
private String sFileName; //Saved File's Name cT,5xp"a
private int nSplitter; //Count of Splited Downloading File o0Pc^
D4W^{/S
X~5kgq0"
public SiteInfoBean() 2=ZZR8v
{//nSplitter的缺省值为5 09C[B+>h
//default value of nSplitter is 5 qaN%&K9F8
this("","","",5); -~ 5|_G2Y"
} d&[.=M\E8
H:&|q+K=#
RB `<Zw
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lhLE)B2a2
{ Kh;jiK !
sSiteURL= sURL; {Tym#
sFilePath = sPath; ILq"/S.
sFileName = sName; YJEL'k<l
this.nSplitter = nSpiltter; wa}\bNKQk
8I*WVa$l
*1fZcw'C.
} .}zpvr8YP
_& qM^
_N&]w*ce
public String getSSiteURL() 9x0Ao*D<t
{ -Y"'=zkO
return sSiteURL; WSPlM"h
} G>fJ)A
T2V# fYCc
(`pd>
public void setSSiteURL(String value) zHsWj^m"
{ crdp`}}
sSiteURL = value; y $K#M
} ZT;:Hxv0N
CH/*MA
7>Oa, \
public String getSFilePath() =Nj58l
{ )FfJ%oT}
return sFilePath; Cyw cJ
} M;i4ss,}!
iqj ZC80
P_f>a?OL:
public void setSFilePath(String value) -}O>m}l
{ =<M7t*!
sFilePath = value; @Yy:MdREA
} cNd2XQB9=
*8*E\nZx!
0bQm:J[(#
public String getSFileName() Q*+_%n1 /
{ ,^_aqH
return sFileName; MFyMo
} gTp){
nPj+mg
DNy1} 3wg
public void setSFileName(String value) Tmo+I4qoL
{ !%x=o&
sFileName = value; fJ?$Z|
} v&>TU(x\H
AF qut
=v$H8w
public int getNSplitter() $^2 j#]uX
{ 1z\>>N$7B
return nSplitter; :z EhPx;B7
} B(GcPDj(K
z5CWgN
o >=YoG
public void setNSplitter(int nCount) 7b2N'^z}
{ 9xvE?8;M#
nSplitter = nCount; i8`&XGEd
} ~?pF'3q
} K%: :
uxq!kF'Ls
nJTV@mXVq
/* aQ ~
**Utility.java VvwQz#S
*/ G;+hc%3y
package NetFox; w@Pc7$EP
4=H/-v'&
a$c7d~p$I
public class Utility { =sP6
wR;_x x
-IR9^)
public Utility() %$ ^yot
{ ^Slwg|t*~P
j.GpJDq
~>@Dn40
} n8zh;vuJ
A$RN7#
//线程睡眠 A"V3g`dP
public static void sleep(int nSecond) lqOv_q
{ 47"ERfP
try{ %S22[;v{N
Thread.sleep(nSecond); #gOITXKs
} '3wte9E/
catch(Exception e) r4O*0Q_
{ bwo"s[w
e.printStackTrace (); voaRh@DZ%/
} }k}5\%#li5
} $Q|66/S^
0Bn$C,-
//日志 EOV<|WF>
public static void log(String sMsg) xH\'gli/
{ `3r*Ae
System.err.println(sMsg); ~K^Z4
} G%anot
knypSgk_
8k+Ctk
public static void log(int sMsg) '<m[
{ 3}$L4U
System.err.println(sMsg); (~{7e/)r
} iD@2_m)
} 2:i`,
Vm&fw".J
4 !~JNO
/* Cs%'Af
**TestMethod.java ~@R=]l"
*/ x&)P)H0vn
package NetFox; \u,hS*v0
e&F,z=XJ}
LP_!g
public class TestMethod { >'Nrvy%&0
9ZG.%+l
$K\\8$Z
public TestMethod() 7P]_03
{ ///xx/weblogic60b2_win.exe y{K~g<VL
try{ .he%a3e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 34]f[jJ|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p%J,af
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y cOtPS%
fileFetch.start(); *BBP"_$
} :?jOts>uP
catch(Exception e){e.printStackTrace ();} 3,tKqR7g
-YHlVz
~b8U#'KD
} Z'WoChjM
]t7<$L
)#Y*]
public static void main(String[] args) <8r%_ ']
{ T\8|Q@
new TestMethod(); nd_d tsp#
} InNuK0@
} im%'S6_X4
点击下载更多相关资料