http断点续传简单实现（java)

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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)); G&2`c\u{
} ;H;c Sn5uL
for(int i=0;i<nEndPos.length-1;i++) o,yP9~8\
{ 1o*eu&@
nEndPos = nStartPos[i+1]; :497]c3#5C
} pX~X{JTaL)
nEndPos[nEndPos.length-1] = nFileLength; gJUawK
} ndCHWhi
} &W@#pG
K[~fpQGbV1
mv;;0xH
//启动子线程 -{ M(1vV(=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Hk8pKpn3
for(int i=0;i<nStartPos.length;i++) `C+>PCO
{ 1U(P0$C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8+yCP_Y4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ] eO25,6
nStartPos,nEndPos,i); Dq:>]4%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +i0j3.
fileSplitterFetch.start(); 8pZGu8
} mufJ@YS#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `: R7jf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7I0[Ii
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S(\<@S&
nEndPos = " + nFileLength); w#Di
// fileSplitterFetch[nPos.length-1].start(); MJDW-KL-
44p?x8(z*
ZS\~GQbG
//等待子线程结束 V^[B=|56
//int count = 0; Q]v><
//是否结束while循环 8,DY0PGP
boolean breakWhile = false; 9J $"Qt5;6
2YV*U_\L
oM~;du
while(!bStop) e"@Ag:r@a
{ ,N`cH\
write_nPos(); 5_\+8A*
Utility.sleep(500); +IkL=/';#
breakWhile = true; -Y=o
@7j$$
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for(int i=0;i<nStartPos.length;i++) z 7 s&7)a
{ (- QvlpZ
if(!fileSplitterFetch.bDownOver) XJI ff$K
{ 5H!6#pqM
breakWhile = false; 1@"os[9
break; lc8zF5
} abgAUg)
} DbIn3/WNe
if(breakWhile) W~i599!v
break; =(cfo_B@K
7(W"NF{r
snm1EPj
//count++; u#^~([I
//if(count>4) $FM:8^
// siteStop(); A]_5O8<buW
} G%#M17
/ho7O/aAa
P'<D0
System.err.println("文件下载结束！"); W0qn$H
} >5c38D7k)
catch(Exception e){e.printStackTrace ();} ?Zv>4+Y'
} ["7]EW\!:
>)6d~
lVra&5
//获得文件长度 p/WE[8U
public long getFileSize() .wvgHi
{ $z[r(a^a
int nFileLength = -1; kX8Ey
try{ Q@aDa8Z
URL url = new URL(siteInfoBean.getSSiteURL()); 1kdQh&~G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tYST&5Kh~
httpConnection.setRequestProperty("User-Agent","NetFox"); |Zm'!-_
JuM4Njz|
O;CC(
int responseCode=httpConnection.getResponseCode(); 1}XESAX;0
if(responseCode>=400) 9JBVG~m+
{ 25wvB@0&
processErrorCode(responseCode); >uy(N
return -2; //-2 represent access is error ;/s##7qf
} &wea]./B
Zg;%$ kSQ
3"HX':8x
String sHeader; \s^4f#
[Zj6v a
Cj1nll8c
for(int i=1;;i++) DR c-L$bD
{ 5ji#rIAhxh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }F=lG-x
//Utility.log(in.readLine()); .h=H?Hr(V]
sHeader=httpConnection.getHeaderFieldKey(i); m#a1N
if(sHeader!=null) <4,LTB]9-
{ g7@.Fa.u'!
if(sHeader.equals("Content-Length")) 2{oU5e
{ ;{:bq`56f
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f*E#E=j
break; V \Sl->:
} a"bael
} #.W^7}H
else JthW"{E
break; Q)L6+gW^
} W~Ae&gcn#
} v FWg0 $,
catch(IOException e){e.printStackTrace ();} gBd@4{y6C.
catch(Exception e){e.printStackTrace ();} dO!5` ]
(_Ky'.
1!p7N$QR
Utility.log(nFileLength); * G0I2
.F^372hH3
7L !$hk
return nFileLength; ;+(EmD:Q
} .g8db d
r";;Fk#5
y|2y!&o,!
//保存下载信息（文件指针位置） @l %x;`E
private void write_nPos() G^&P'*
{ b 67l\L
try{ cu )w6!f
output = new DataOutputStream(new FileOutputStream(tmpFile)); wq =Ef
output.writeInt(nStartPos.length); .ovG_O
for(int i=0;i<nStartPos.length;i++) "?r_A*U
{ >&D}^TMYY
// output.writeLong(nPos); Xcw6mpLt
output.writeLong(fileSplitterFetch.nStartPos); NGL,j\(~7
output.writeLong(fileSplitterFetch.nEndPos); Q~zs]{\
} `FHKQS5
output.close(); ?my2dd,|
} aM!%EaT
catch(IOException e){e.printStackTrace ();} )m<CmYr2
catch(Exception e){e.printStackTrace ();} =)IV^6~b
} Pt\GVWi_t
HMl M!Xk?
H}PZJf_E
//读取保存的下载信息（文件指针位置） nk.j7tu
private void read_nPos() FfpP<(4
{ 'v0(ki#
try{ 7(plHW|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i(an]%'v
int nCount = input.readInt(); YF68Ax]
nStartPos = new long[nCount]; Ac8t>;=&
nEndPos = new long[nCount]; vNSeNS@jxC
for(int i=0;i<nStartPos.length;i++) Ee097A?1vj
{ gH:+$FA
nStartPos = input.readLong(); |?<^4U8
nEndPos = input.readLong(); f`bRg8v
} c$b~?Mx
input.close(); {N'<_%cu
} Y0xn}:%K
catch(IOException e){e.printStackTrace ();} SI9PgC
catch(Exception e){e.printStackTrace ();} ?G<.W[3
} 49-wFF
<Wa7$hF
\Y^GA;AMQQ
private void processErrorCode(int nErrorCode) "a=dx| Z
{ ~U+W4%f8
System.err.println("Error Code : " + nErrorCode); e!oL!Zg
} z#Db~
|"i"8~/@<
Yx':~
//停止文件下载 nNpXkI:
public void siteStop() PsO>&Te2
{ 3e ?J#;
bStop = true; e_3($pj
for(int i=0;i<nStartPos.length;i++) 5#BM
fileSplitterFetch.splitterStop(); l dw!G/
W,bu=2K6
$*c!9Etl4
} @BoZZ
} ?F/)<r
//负责部分文件的抓取 .kp3<.
**FileSplitterFetch.java Kdr}7#c
*/ sj8lvIY5
package NetFox; dLtmG:II
b:(t22m#?
%6cbHH
import java.io.*; bBgyLyg
import java.net.*; {4YD_$4W
4b 1a?
"9O8#i<Nr
public class FileSplitterFetch extends Thread { >gf,8flgj
V#TNv0&0
Z7J4rTA
String sURL; //File URL I/)*pzt8
long nStartPos; //File Snippet Start Position N?><%fra
long nEndPos; //File Snippet End Position ~'VVCtA
int nThreadID; //Thread's ID a Juv{
boolean bDownOver = false; //Downing is over @Zw[LIQ*
boolean bStop = false; //Stop identical mu$rG3M
FileAccessI fileAccessI = null; //File Access interface (7w95xI
K:54`UJ
N4$ K{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ls/*&u
{ rj/1AK
this.sURL = sURL; L!0}&i;u~5
this.nStartPos = nStart; r;@"s g
this.nEndPos = nEnd; SlI wLv^
nThreadID = id; 2U&+K2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x<1t/o
} #+(@i|!ifo
Rh%C$d(
5`Y>!| Ab
public void run() !dOpLUh l
{ C=x70Y/
while(nStartPos < nEndPos && !bStop) ,jdTe?[*^
{ 52.%f+Oa
349BQ5ND
iiv`ji
try{ C@!bd+'
URL url = new URL(sURL); Dn:1Mtj-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _71&".A
httpConnection.setRequestProperty("User-Agent","NetFox"); ?$.x%G+
String sProperty = "bytes="+nStartPos+"-"; cf%aOHYI*
httpConnection.setRequestProperty("RANGE",sProperty); E'^ny4gL
Utility.log(sProperty); SS!b`
<['ucp
?\_vqW
InputStream input = httpConnection.getInputStream(); lY[\eQ 1:
//logResponseHead(httpConnection); @nOuFX4
2[i(XG{/
(&Mv!6]
byte[] b = new byte[1024]; FZtT2Z4&i
int nRead; L b-xc]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N9 TM
{ ;^cMP1SH
nStartPos += fileAccessI.write(b,0,nRead); )WsR 8tk
//if(nThreadID == 1) +2g}wH)l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ta0;:o?/d
} qJ[wVNHh!
`.3{
,:% h`P_
Utility.log("Thread " + nThreadID + " is over!"); {hVc,\A
bDownOver = true; :eFyd`Syw
//nPos = fileAccessI.write (b,0,nRead); *Rgl(Ba
} /Nns3oE
catch(Exception e){e.printStackTrace ();} %e+{wU}w?2
} E&>;a!0b]
} 9F7}1cH7g@
XwDt8TxL
Mo]aB:a
//打印回应的头信息 >%A~ :
public void logResponseHead(HttpURLConnection con) y(X^wC
{ S^{tRPF%d
for(int i=1;;i++) c3(0BSv
{ s:ojlmPb
String header=con.getHeaderFieldKey(i); YM#J_sy@J.
if(header!=null) ]l^"A~va
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <K <|G
Utility.log(header+" : "+con.getHeaderField(header)); <SiJA`(7
else Lw`}o`D
break; uTvf[%EHW
} 0u bf]Z
} SK5__Ix
zvwv7JtB
}ISR +./+
public void splitterStop() vHN/~k#
{ \m(>Q
bStop = true; MbeK{8~E%l
} Z/LYTo$Bz
9Us'Q{CD
vdd>\r)v
} \`W8#fob
j43i:c;F
rh T!8dTk
/* Iv/h1j> H
**FileAccess.java 83F]d+n
*//文件访问(定位，写) u.2^t:A
package NetFox; ?ZYj5[op,H
import java.io.*; p+V::O&&r
\O)u' Bu
$]MOAj"LH
public class FileAccessI implements Serializable{ U04)XfO;]
!,{-q)'D
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -BH T'zq1S
RandomAccessFile oSavedFile; \~.elKw<U
long nPos; n<Ki.;-ZE
@%!Gj{
Mo\nY5
public FileAccessI() throws IOException z8 K#G%,:
{ vH@$?b3VP
this("",0); R)Dh;XA
} o<rbC < U
!L)yI#i4C
`+(4t4@ew
public FileAccessI(String sName,long nPos) throws IOException 7e /Kh)5G
{ VM+l9z>
oSavedFile = new RandomAccessFile(sName,"rw"); G{0f* cH)
this.nPos = nPos; !J(6E:,b#
oSavedFile.seek(nPos); M1I4Ot
} r@ba1*y0
z5W;-sCz
J7k=5Fqej;
public synchronized int write(byte[] b,int nStart,int nLen) zwK$ q=-:
{ W3&~[DS@~
int n = -1; Ox6^=D"
try{ TSj)XU {W
oSavedFile.write(b,nStart,nLen); \b?O+;5Cj
n = nLen; XlJ+:st
} 1~[GGl
catch(IOException e) ~e=KBYDBu
{ S9 @*g3
e.printStackTrace (); 5K00z?kD2V
} M] W5%3do
10*^
wV'_{/WM
return n; =<U'Jtu6'
} sNJ?Z"5k1h
PcvA/W
F2v9XMi
} \$ :)Ka
.&/A!3pW
f0g&=k{OD
/* \8`^QgV`@
**SiteInfoBean.java kp*BAQ
*/ H}lbF0`
package NetFox; +'UxO'v3]
t_Ul;HVPS
+Q!Kj7EU/
public class SiteInfoBean { (ewcj\l4*
IXsOTBM
/_r{7Gq.
private String sSiteURL; //Site's URL a2H_8iQ!
private String sFilePath; //Saved File's Path Q]-r'pYr
private String sFileName; //Saved File's Name =GLMdhD]
private int nSplitter; //Count of Splited Downloading File s_76)7
I2C1mV
l6!a?C[2T
public SiteInfoBean() r`C t/]c
{//nSplitter的缺省值为5 XNkQ0o0
//default value of nSplitter is 5 7` t,
this("","","",5); ? \NT'CG
} 0!`!I0
eb<'>a
g=s2t"&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) X($@E!|
{ ,@t#)HV
sSiteURL= sURL; (ce"ED`1
sFilePath = sPath; v9Ez0 :)
sFileName = sName; bM $WU?Z
this.nSplitter = nSpiltter; 'Y5=A!*@tf
62#8c~dL
=4Wjb
} k?=_p6>
G_?qY#"(
'deqF|Iox
public String getSSiteURL() zuvP\Y=V`
{ jce2lXMm
return sSiteURL; n/IDq$/P
} r-o6I:y
!Ly1!;<
j,#R?Ig
public void setSSiteURL(String value) 7,3v,N|
{ IF|%.%I$!U
sSiteURL = value; x[2eA!NC
} .?.Q[ic
9|//_4]
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public String getSFilePath() 2LH.If
{ #NWc<Dd
return sFilePath; /f -\ 3
} JC4Z^/\.
}C&kzJBEF
.gd'<l
public void setSFilePath(String value) j(\jYH>
{ SL>0_
sFilePath = value; O)G^VD s
} U+g<lgH1J
vjD||!g'
on0>_-n)
public String getSFileName() Y ptP_R:2p
{ sTO9>~sj
return sFileName; (1Ii86EP
} !6d`e"\K
z@J;sz
lF!Iu.MM 9
public void setSFileName(String value) -44''w?z
{ !u|s|6{\
sFileName = value; Sc&p*G
} #[Vk#BIiv8
pJ]i)$M
1fb!sbGD.k
public int getNSplitter() `oo(\O7t=
{ KR/SMwy
return nSplitter; *7 >K"j
} -AU!c^-o
9~WjCa*,&
yn-TN_/Y,
public void setNSplitter(int nCount) L\X2Olfz1
{ 8p~G)J3U
nSplitter = nCount; D[}qhDlX
} VcR(9~
} M]OZS\9.B
4f> s2I&pQ
%q 7gl;'
/* n+uDg
**Utility.java h^"OC$
*/ I%31MU9
package NetFox; pwO U6A!
j#E&u*IR
|\ 4cQ
public class Utility { B":u5_B
W02swhS
4PAuEM/z
public Utility() <',bqsg[
{ Lj03Mx.2S
VtD:'L-
6,;7iA]
} FrryZe=
@^kt[$X;
//线程睡眠 KN9e""
public static void sleep(int nSecond) Acib<Mi2!-
{ 5 MD=o7O^
try{ tB7g.)yZb
Thread.sleep(nSecond); x(/{]$h
} iSxuor^;
catch(Exception e) VVyms7 VN
{ p8Wik<'^
e.printStackTrace (); MUd 9R
} _-/<bO
} AjA.="3
DQOEntw
//日志 ",qJG]_ <
public static void log(String sMsg) 9n[ovX 7n!
{ s0x;<si_
System.err.println(sMsg); #y&O5
} L@HWm;aN
n:wZL&ZV0
Z>zW83a
public static void log(int sMsg) G;3N"az
{ OwM.N+z#T
System.err.println(sMsg); 1W +QcK4k
} D/-$~u_o
} c$HZvv
Td6"o&0A!
Fz4g:8qdA
/* e[a?5,s2
**TestMethod.java U}Aoz|
*/ _Q1[t9P"
package NetFox; >'X[*:Cx
60 z =bd]
<c&6M
public class TestMethod { / !*+9+h
)2jBhT
9c_h+XN?y
public TestMethod() *N#{~
{ ///xx/weblogic60b2_win.exe k)l^;x-
try{ VU[4 W8f
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ry%Fs&V*>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #n8jn#
SiteFileFetch fileFetch = new SiteFileFetch(bean); Wa|lWIMK
fileFetch.start(); %"0g}tK6
} -O?}-6,_Z
catch(Exception e){e.printStackTrace ();} `Mp-4)mn
z_LN*u
&_N$S2
} b\O%gg\p%!
i>`!W|=_
psZAO,p
public static void main(String[] args) .\X;VWTI
{ ^1^muc[
new TestMethod(); T1Q c?5K^
} Tn7(A^h'
} UoiXIf_Q
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