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)); _KD5T4FZR
} ;PyZ?Z;
for(int i=0;i<nEndPos.length-1;i++) q|)Q9+6$+
{ #2xSyOrmf
nEndPos = nStartPos[i+1]; <ale$[
} W0cgI9=9
nEndPos[nEndPos.length-1] = nFileLength; insY(.N
} }vt%R.u
} tK%c@gGU9
B ?%L
]|:uU
//启动子线程 jQj,q{eA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z"I/ NGiU
for(int i=0;i<nStartPos.length;i++) `xKFqx:e
{ 34|a:5c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8Og3yFx[rt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), sNU}n<J-
nStartPos,nEndPos,i); V7t!?xOL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g\M5:Qm
fileSplitterFetch.start(); qS8B##x+=
} *9gD*AnM,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u2sR.%2U<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #^mqQRpgq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", KhM.Tc
nEndPos = " + nFileLength); XY+y}D %
// fileSplitterFetch[nPos.length-1].start(); *i<\iMoW
^i_Iqph=
Jfg7\&|
//等待子线程结束 s'_,:R\VM>
//int count = 0; @C.GKeM*
//是否结束while循环 aU<s<2O)
boolean breakWhile = false; /r.6XZs6
r[HT9
>#N[GrJAE
while(!bStop) XizPMN5a
{ R,Ml&4pZ}
write_nPos(); vD=%`G[m
Utility.sleep(500); ; Zq/eiB
breakWhile = true; dbO#
MD'>jO;n
e.X@] PQJQ
for(int i=0;i<nStartPos.length;i++) kX8=cL9G
{ Fh`-(,e?5
if(!fileSplitterFetch.bDownOver) \f"?Tv-C'
{ Q\#UWsN(T/
breakWhile = false; elbG\qXBp
break; vR]mSX3)?
} /4C`k=>
} .[f;(WR
if(breakWhile) R [9w
break; g@E&uyM
oBw}hH,hp
]P*!'iYN(
//count++; 0>Fqx{!heq
//if(count>4) R$xY8+}V
// siteStop(); K/Jk[29"\
} 2X_>vIlEm
;c)! @GoA
T}2:.Hk:N
System.err.println("文件下载结束！"); ~V$ f#X
} eU~?p|Np
catch(Exception e){e.printStackTrace ();} t F/nah
} 46dc.Yi
2v\W1VF
h[H%:743
//获得文件长度 yqBa_XPV8
public long getFileSize() "%kGRHq
{ ITn;m
int nFileLength = -1; 1"$R 3@s;
try{ qvTKfIl{
URL url = new URL(siteInfoBean.getSSiteURL()); oeGS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FF@`+T
httpConnection.setRequestProperty("User-Agent","NetFox"); xA9V$#d|
x3;jWg~'
VIYV92[
int responseCode=httpConnection.getResponseCode(); %1Jd^[W
if(responseCode>=400) eE,;K1
{ gA:[3J,[;
processErrorCode(responseCode); /h-6CR Ka
return -2; //-2 represent access is error !5E9sk{)
} .xnQd^qoac
z'e1"Y.
9,KVBO
String sHeader; {]@Qu"M
Fd}<Uote3
X}?ESjZJ
for(int i=1;;i++) fOJj(0=y
{ L"9 Gc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s+N^PX3
//Utility.log(in.readLine()); @LHtt/&
sHeader=httpConnection.getHeaderFieldKey(i); taixBNv
if(sHeader!=null) sM0c#YK?
{ <%/:w/
if(sHeader.equals("Content-Length")) !4L#$VG
{ ,0FwBK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tNYJQ
break; &R0OeRToUb
} +&?'KZ+Z_v
} j]#wrm
else pB[%:w/@l:
break; at=D&oy4"+
} G+fd.~aGE
} 8 `o{b"l+
catch(IOException e){e.printStackTrace ();} .?70=8{
catch(Exception e){e.printStackTrace ();} q?1yE@th
4 ;^g MI9
m^5s>hUl
Utility.log(nFileLength); XEa~)i{O
bD d_}
BZ2nDW*%
return nFileLength; /!:L7@BZ
} |z]aa
xa' nJ"f;
Euqjxz
//保存下载信息（文件指针位置） 8IpxOA#jQ
private void write_nPos() l#p}{
{ ofVEao
try{ P_v0))n{
output = new DataOutputStream(new FileOutputStream(tmpFile)); $R8>u#K!
output.writeInt(nStartPos.length); C0P*D,
for(int i=0;i<nStartPos.length;i++) ^zKt{a
{ #"|"cYi,
// output.writeLong(nPos); ?VUgwP_=
output.writeLong(fileSplitterFetch.nStartPos); ~v^%ze
output.writeLong(fileSplitterFetch.nEndPos); E`Q;DlXv>
} Ii,~HH
output.close(); ;5-R=e(KA
} 9e0C3+)CY
catch(IOException e){e.printStackTrace ();} Wk7L:uK
catch(Exception e){e.printStackTrace ();} U.HoFf+HN
} F\zkyk4
z|Hy>|+
"[#@;{@Gt
//读取保存的下载信息（文件指针位置） B{[f}h.n
private void read_nPos() ^).WW
{ vYYS.ve
try{ Y>xi|TWN
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MV% :ES?
int nCount = input.readInt(); f37ji
nStartPos = new long[nCount]; X\o/i\ C}
nEndPos = new long[nCount]; dMey/A/VYt
for(int i=0;i<nStartPos.length;i++) 0m]~J_
{ tniPEmeS
nStartPos = input.readLong(); Y')O>C0~
nEndPos = input.readLong(); [`y:M&@
} A4~D#V
input.close(); Vf"O/o}hq,
} IOSuaLH^
catch(IOException e){e.printStackTrace ();} UOn!Y@
catch(Exception e){e.printStackTrace ();} BM|-GErE
} 6U;Jg_zS
Cf.pTYSl
"Czz,;0
private void processErrorCode(int nErrorCode) pe\Txg6
{ 9(QU2QY
System.err.println("Error Code : " + nErrorCode); "bHtf_
} &>&dhdTQ
ipx@pNW;"
h5LJijJ
//停止文件下载 ,:0Q1~8
public void siteStop() /Ki0+(4
{ XR{5]lKt_
bStop = true; dH ^b)G4
for(int i=0;i<nStartPos.length;i++) se<i5JsSV
fileSplitterFetch.splitterStop(); Paae-EmC
2(+RIu0d
)![f\!'PI
} 5W?yj>JR
} Y|hzF:ll
//负责部分文件的抓取 <7vIh0
**FileSplitterFetch.java kGB#2J
*/ }V1DyLg:
package NetFox; 4@/q_*3o
0C7thl{Dms
1Qp1Es<)
import java.io.*; xHM&csL
import java.net.*; <Z\MZ&{k{*
. 1{vpX
9pVf2|5hj
public class FileSplitterFetch extends Thread { {u(}ED#p
"ay,Lr
zxk??0]/
String sURL; //File URL +XU$GSw3(
long nStartPos; //File Snippet Start Position t7U,AQ=;P5
long nEndPos; //File Snippet End Position `@u+u0
int nThreadID; //Thread's ID z/eU^2V
boolean bDownOver = false; //Downing is over 9G`FY:(K
boolean bStop = false; //Stop identical wu&|~@_s@
FileAccessI fileAccessI = null; //File Access interface 6nY )D6$JG
!Zk%P
^'C,WZt
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +LQs.*
{ V'HlAQr
this.sURL = sURL; }\PE {
this.nStartPos = nStart; -7Aw s)
this.nEndPos = nEnd; )|{1&F1
nThreadID = id; =u:6b} =
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /JK-}E
} NE=#5?6%g7
O5G<O(,\
K=!ZI/+ju
public void run() v)C:E9!|
{ j &0fC!k
while(nStartPos < nEndPos && !bStop) V:0uy>
{ lt2Nwt0bv
LAK-!!0X
NU)`js
try{ ,#'o)O#
URL url = new URL(sURL); 'n>3`1E,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =7J|KoKK
httpConnection.setRequestProperty("User-Agent","NetFox"); 764}yV>
String sProperty = "bytes="+nStartPos+"-"; `:bvuc(
httpConnection.setRequestProperty("RANGE",sProperty); Vlp*'2VO
Utility.log(sProperty); (Qh7bfd
$3]E8t
[A%e6
InputStream input = httpConnection.getInputStream(); vS J<
//logResponseHead(httpConnection); x^='pEt{
G0 nH Z6
_#^A:a^e8
byte[] b = new byte[1024]; Z_^Kl76D
int nRead; ax{-Qi7z-+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =-Q
{ TgQ|T57
nStartPos += fileAccessI.write(b,0,nRead); \HP,LH[P:
//if(nThreadID == 1) 'Qs3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -MHX1`P:Sn
} wsb=[$C
'+q'H
(;Q <@PZg
Utility.log("Thread " + nThreadID + " is over!"); U+RCQTo
bDownOver = true; 6ImV5^l
//nPos = fileAccessI.write (b,0,nRead); &h4Z|h[01
} K3r>nGLBo
catch(Exception e){e.printStackTrace ();} ;5oH6{7_Z
} C1Pt3
} H'= i
T`'3Cp$q
Alk* "p
//打印回应的头信息 >gi{x|/
public void logResponseHead(HttpURLConnection con) Uhx2 _
{ CO%O<_C
for(int i=1;;i++) 0.Ol@fO
{ xX4^nem\G
String header=con.getHeaderFieldKey(i); Ff#N|L'9_
if(header!=null) -_4jJxh=OB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); rW%'M#! =
Utility.log(header+" : "+con.getHeaderField(header)); E?q'|f
else ;'18
break; J>|:T
} eUw;!Du
} OB i!fLa
g`8 mh&u%
@Kb|
public void splitterStop() Zn 5m.=z
{ U/&qV"Ih
bStop = true; q}A3"$-F
} -qCJwz30
$XU$?_O
UUEDCtF)
} Pymh^i
a5~C:EU0
uy-Ncy
/* Sl<-)a:
**FileAccess.java Umwg iw
*//文件访问(定位，写) xY'YbHFz
package NetFox; v*]Xur6e}
import java.io.*; A`/7>'k/q[
+#db_k
4aGpKvW
public class FileAccessI implements Serializable{ 7<Js'\Z
(X7yNIPfA
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 IlL
RandomAccessFile oSavedFile; ZXDMbMD
long nPos; qlT:9*&g
gV44PI6h
+~{nU'
public FileAccessI() throws IOException -Izg&u &
{ VM|)\?Q
this("",0); U"kK]Stk<
} W2(=m!:U
)3\rp$]1
zw9ULQ$#
public FileAccessI(String sName,long nPos) throws IOException *ik)>c_
{ G8-d%O p
oSavedFile = new RandomAccessFile(sName,"rw"); uOUw8
this.nPos = nPos; (qONeLf%
oSavedFile.seek(nPos); jtpNo~O
} g^^m a}i
L`@&0Zk
2m}]z.w#
public synchronized int write(byte[] b,int nStart,int nLen) Yy~Dg
{ .z7f_KX^
int n = -1; vjWgR9 4/{
try{ GuDD7~qxY
oSavedFile.write(b,nStart,nLen); 'N/%SRk
n = nLen; ^o<Nz8
} BeCr){,3
catch(IOException e) m,fr?d/;
{ V0B4<TTAo~
e.printStackTrace (); yf>,oNIAg
} zMg^2{0L
r 24]2A
Y(mwJud|
return n; TU6EE
} B|w}z1.
3CL:VwoW
TK1MmL
} X,Q(W0-6$u
#f@53Pxb
!LESRh?
/* +eat,3Ji
**SiteInfoBean.java duTSU9
*/ ^U1+D^AJ
package NetFox; KX@Fgs
@72G*u\Wz
Jx,s.Z0@7,
public class SiteInfoBean { &$ 9bC't6
hD=D5LYAZ
%|||M=akk
private String sSiteURL; //Site's URL ;0WlvKF
private String sFilePath; //Saved File's Path oOw"k*,h:S
private String sFileName; //Saved File's Name Z.:A26
private int nSplitter; //Count of Splited Downloading File TR;-xst@
V!4E(sX
wjs7K|PK
public SiteInfoBean() $xwF;:)
{//nSplitter的缺省值为5 gNBI?xs`p
//default value of nSplitter is 5 oWT0WS
this("","","",5); dDTt_B
} :DP{YL|x
3x$#L!VuU
n+w>Qz'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \^D`Hvg
{ pwQ."2x
sSiteURL= sURL; *0tNun 5=3
sFilePath = sPath; (["u"m%
sFileName = sName; ekXHfA!i%
this.nSplitter = nSpiltter; nfU}ECun4
GQQ6 t
Si(?+bda0c
} -8:@xG2
\(s";@
>U].k8a)
public String getSSiteURL() ]y/:#^M+
{ ^ +G> N
return sSiteURL; UKdzJEhG
} KA7nncg;,
mD:!"h/
2TO1i0
public void setSSiteURL(String value) N[%IrN3
{ %\u>%s<9
sSiteURL = value; -b<+Ra
} y+_U6rv[
01b0;|
lwlR"Z
public String getSFilePath() {1mD(+pJ{
{ CEiGjo^
return sFilePath; NoT oLt\
} qp8;=Nfa
#=2~MXa@z7
Qoc-ZC"<6
public void setSFilePath(String value) YZd4% zF
{ .#SWfAb2h
sFilePath = value; u=5^xpI<D
} pE#0949
!|]%^G
O-RiDYej
public String getSFileName() xK f+.6 wz
{ R[6&{&E:
return sFileName; q0o6%c:gW
} 3i<*,@CY
W/+0gh7`,(
!^%b|=[
public void setSFileName(String value) i=+ "[h^
{ M~v{\!S
sFileName = value; A-kI_&g\Og
} Ngr7E
3Dy.mtP
Xv6s,<#\
public int getNSplitter() 1*s Lj#
{ BX?Si1c
return nSplitter; }Q*8QV
} !GO4cbdQ
/PO5z7n0J
!,]_tw>R
public void setNSplitter(int nCount) p AD@oPC
{ y37@4p^@9
nSplitter = nCount; k;]&`c^5
} a`}HFHm\2,
} u(P D+Gz
XWk^$"
|zSkQ_?54
/* NVQIRQ.
**Utility.java PR6{Y]e%
*/ 6HyQm?c>a
package NetFox; ,+f'%)s_x
=6ojkTk
.Sm7na K
public class Utility { s iC/k*
V7.EDE2A3
cu|{cy-
public Utility() dx|j,1e
{ 8{'L:yzMY
~%'M[3Rb
Vg0Rc t
} rTQrlQ:@
!-[e$?-
//线程睡眠 XvWUJ6M
public static void sleep(int nSecond) hl8[A-d(R
{ =MA$xz3
try{ !fY'^Ya?
Thread.sleep(nSecond); ka655O/)&
} PKk_9Xd
catch(Exception e) {qK>A?9
{ y<MXd,eE
e.printStackTrace (); =*fOej>G
} n"*A.
} Y'wQ(6ok
&G:#7HX@-
//日志 B\`4TU}kE
public static void log(String sMsg) w\!aKeP'
{ _3.=| @L
System.err.println(sMsg); M"W-|t)~
} It&$R`k
C0J/FFBQ^
M, f6UYo=
public static void log(int sMsg) rxJmK$qd
{ Q#i[Y?$L
System.err.println(sMsg); *>I4X=
} p@0Va
} )cxLpTr
f5'Cq)Vw_
8tJB/Pw`S
/* 0e-M 24,C
**TestMethod.java EVX*YGxx6
*/ *Yj!f68
package NetFox; yy8h8{=g
k <SFl
8iQ8s;@S&>
public class TestMethod { /x\{cHAt8J
#l2KJ7AMK
YBF|0A{[Y
public TestMethod() AUBZ7*VO
{ ///xx/weblogic60b2_win.exe dz_~_|
try{ hhRUC&Y%V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); v"-@'qN'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); vuN!7*d+
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ls51U7
fileFetch.start(); ?o$ hlX
} ,%Sf,h?"^
catch(Exception e){e.printStackTrace ();} _=$:<wIE[
Ts)ox}rYVm
L{&5Ets
} o>~xrV`E
x:dI:G
@~g][O#Fu
public static void main(String[] args) T3H\KRe6
{ P~xP@?I%
new TestMethod(); 3Q;XvrGA
} 7UnB]-:.
} %OT}r
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