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)); FV{XPr%
} "ji+~%`^[t
for(int i=0;i<nEndPos.length-1;i++) 8T[<&<^-
{ Cu_-QE
nEndPos = nStartPos[i+1]; yq1G6hw
} +|TXKhm{
nEndPos[nEndPos.length-1] = nFileLength; '2UQN7@d
} 06?d#{?M1o
} Gzs$0Ki=
Y[W:Zhl;
1vS-m x
//启动子线程 {vT9I4d8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ";/ogFi
for(int i=0;i<nStartPos.length;i++) )i_:[ l6
{ de;CEm<n
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Vt,P.CfdC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !N!AO(Z
nStartPos,nEndPos,i); )Cat$)I#,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 13*S<\
fileSplitterFetch.start(); D]5j?X'
} x&r f]R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?6HnN0A)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); IVVX3RI
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5tk7H2K^<
nEndPos = " + nFileLength); *!j!o%MB
// fileSplitterFetch[nPos.length-1].start(); J/3$I
6J">@+
F%.UpV,
//等待子线程结束 ~=I:go
//int count = 0; y0p\Gu;3j
//是否结束while循环 a!f71k r
boolean breakWhile = false; ^Pah\p4bj
+~=j3U
Y/?z8g'p
while(!bStop) LXZI|K[}k
{ `5"3Cj"M
write_nPos(); 9m\Yi
Utility.sleep(500); uKj(=Rqq
breakWhile = true; d^zuo
wEN[o18{
m77!i>V)
for(int i=0;i<nStartPos.length;i++) G:@1.H`
{ sk*vmxClY
if(!fileSplitterFetch.bDownOver) i|xz
{ .&`apQD}
breakWhile = false; nwzyL`kF
break; |>1#)cONW
} Cs\jPh;"
} ;/kmV~KG
if(breakWhile) H}q$6WE
break; -8R SE4)
uvw1 _j?
@yC3a)=$L
//count++; gI"cZ h3}
//if(count>4) x 0#u2j?zj
// siteStop(); 3_.%NgES|
} ~)zxIO!
r8!pk~R5]
}8s&~fH
System.err.println("文件下载结束！"); _g-0"a{-
} ]h=5d09z
catch(Exception e){e.printStackTrace ();} @= =)
} n&DBMU
sZ7~AJ
j)#yyK{k2s
//获得文件长度 )eqF21\
public long getFileSize() 6urU[t1
{ _/u(:
int nFileLength = -1; ((<\VQ,>(
try{ {[hgSVN;
URL url = new URL(siteInfoBean.getSSiteURL()); \Lg4Cx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0cVxP)J+
httpConnection.setRequestProperty("User-Agent","NetFox"); mIPDF1=)
{+[Ex2b$
j(}pUV B
int responseCode=httpConnection.getResponseCode(); WF_QhKW|k
if(responseCode>=400) Mz+vT0
{ fL("MDt
processErrorCode(responseCode); cd=K=P}p
return -2; //-2 represent access is error NciIqF
} Pc7p2
ruyQ}b:zS
mNEh\4ai
String sHeader; O%6D2d
TP~1-(M)}
xE$lx:C"FU
for(int i=1;;i++) C\vOxBAB
{ ,yvS c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tOxH9
//Utility.log(in.readLine()); q~Al[`K
sHeader=httpConnection.getHeaderFieldKey(i); FMhuCl2
if(sHeader!=null) )4.-6F7U?
{ ^FVmP d*1
if(sHeader.equals("Content-Length")) K4+|K:e
{ 71ab&V il
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +@H{H2J4
break; M{jq6c
} YpRhl(|
} GV28&!4sS
else UX<)hvKj
break; pf+VYZ#)
} SqdI($F\:
} -M_>]ubG
catch(IOException e){e.printStackTrace ();} xI/8[JW*
catch(Exception e){e.printStackTrace ();} s:(z;cj/
'KT(;Vof
2;J\Z=7
Utility.log(nFileLength); '#eT
WK@<#
}TAG7U*
return nFileLength; -_eG/o=M
} RCxwiZaf33
E H%hL5(
5hDy62PRr
//保存下载信息（文件指针位置） [N}QCy
private void write_nPos() 25j\p{*
{ lC,~_Yb
try{ 6`bR' 0D
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]*Q,~uV^|
output.writeInt(nStartPos.length); <P6d-+
for(int i=0;i<nStartPos.length;i++) H*+7{;$
{ ;:+2.//
// output.writeLong(nPos); n}fV$qu
output.writeLong(fileSplitterFetch.nStartPos); yy&L&v'
output.writeLong(fileSplitterFetch.nEndPos); kHhku!CH
} ^U96p0H"T
output.close(); e@ $|xa")
} oA7|s1
catch(IOException e){e.printStackTrace ();} h@\HPYi#.
catch(Exception e){e.printStackTrace ();} b!`Ze~V
} r.6?|
='_3qn.
i\gt @
//读取保存的下载信息（文件指针位置） _-^mxC|M
private void read_nPos() [TFp2B~)#
{ 7^mQfQv
try{ Ap;^\5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -T-yt2h(
int nCount = input.readInt(); Z glU{sU
nStartPos = new long[nCount]; Zk>m!F>,p
nEndPos = new long[nCount]; a/3'!}&e
for(int i=0;i<nStartPos.length;i++) JnIG;/
{ inZ0iU9dy
nStartPos = input.readLong(); XW@C_@*J
nEndPos = input.readLong(); q(L.i)w$
} o_[~{@RoR
input.close(); H@~tJ\L
} gs0`nysM#
catch(IOException e){e.printStackTrace ();} p~""1m01,D
catch(Exception e){e.printStackTrace ();} Sm?|,C3V
} YI> xxWA
LU`)
Fp[49
private void processErrorCode(int nErrorCode) ]gm3|-EiY
{ q5@Nd3~h
System.err.println("Error Code : " + nErrorCode); 51H6 W/$
} _@gg,2 u-
}9#GJ:x`
bAuiMw7!
//停止文件下载 V[kn'QkWv
public void siteStop() L~by`q N_
{ jG)66E*"
bStop = true; 0Zo><=
for(int i=0;i<nStartPos.length;i++) vv<\LN0
fileSplitterFetch.splitterStop(); Z7[S698
J^%E$s
~Fl\c-
} D/%v/mpj$
} ~ _tK.m3
//负责部分文件的抓取 }J92TV
**FileSplitterFetch.java !?Y71:_!
*/ {4f%UnSz(
package NetFox; pv&iJ7RN
es\ qnq
8ph1xQ'
import java.io.*; pY&dw4V
import java.net.*; d(R8^v/L
Fm6]mz%~u#
GK6CnSV8d
public class FileSplitterFetch extends Thread { x!pd50-
)1R[X!KQ7
ImH9 F\
String sURL; //File URL 0Q8iX)
long nStartPos; //File Snippet Start Position A )CsF
long nEndPos; //File Snippet End Position ,1lW`Krx
int nThreadID; //Thread's ID hNgT/y8
boolean bDownOver = false; //Downing is over !W0JT#0
boolean bStop = false; //Stop identical Eb63O
FileAccessI fileAccessI = null; //File Access interface X}C8!LA
R~hIoaiN
Z?3B1o9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Yl$@/xAa
{ l[m*csDk"
this.sURL = sURL; H1KXAy`&
this.nStartPos = nStart; >1]hR)Ip
this.nEndPos = nEnd; sCQV-%9
nThreadID = id; ^T1caVb|>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KV9~L`=]i
} gSyBoY
$#W^JWN1
v$(Z}Hg
public void run() [Fk|m1i!
{ qs_cC3"=%=
while(nStartPos < nEndPos && !bStop) /RxqFpu|.
{ p|a`Q5z!
0oBAJP
0]]OE+9<c
try{ 6cbV[!BL
URL url = new URL(sURL); NiE`u m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _D8 zKp
httpConnection.setRequestProperty("User-Agent","NetFox"); O*,O]Q
String sProperty = "bytes="+nStartPos+"-"; e7&RZ+s#wZ
httpConnection.setRequestProperty("RANGE",sProperty); wc"~8Ah
Utility.log(sProperty); }j2t8B^&:
'.S02=/
{Dy,|}7s
InputStream input = httpConnection.getInputStream(); b'R]DS{8
//logResponseHead(httpConnection); .W2w/RayC
mL'A$BR`
QyZ'%T5J
byte[] b = new byte[1024]; ]iFW>N*a
int nRead; D@[#7:rHL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @ptrF pSL
{ [O!/hppN
nStartPos += fileAccessI.write(b,0,nRead); ?6x&A t
//if(nThreadID == 1) .RmoO\ ,Gm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p<l+js(5|
} 3!QXzT$E
Xa$%`
*H=h7ESq
Utility.log("Thread " + nThreadID + " is over!"); !O'p{dj][
bDownOver = true; JnnxXj30,
//nPos = fileAccessI.write (b,0,nRead); o: > (Tv
} U-f8D
catch(Exception e){e.printStackTrace ();} ?>vkY^/
} O~x{p,s U
} ;<E?NBV^
]rg-=Y k
ymqn1ja1
//打印回应的头信息 n: {f\
public void logResponseHead(HttpURLConnection con) <4/q5*&
{ |q\i, }
for(int i=1;;i++) cSG(kFQ
{ s+G(N$0U
String header=con.getHeaderFieldKey(i); dpt P(H
if(header!=null) ZGCp[2$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \RFA?PuY
Utility.log(header+" : "+con.getHeaderField(header)); /;21?o
else &f?JtpB
break; EKsOj&ZiJ
} HAs/f#zAk6
} 1L\r:mx3
Py+ B 2G|
q$}J/w(,
public void splitterStop() ~=oCou`XF
{ =_Z.x&fi
bStop = true; j"zW0g!S
} ;>X;cZMd
+G7[(Wz(z
7suT26C
} j-FMWEp
JPgFTr
d+ $:u
/* 3(.Y>er%U
**FileAccess.java k{ZQM
*//文件访问(定位，写) I,& gKgh
package NetFox; Jiru~Vo+
import java.io.*; b#t5Dve
XQ}7.u!
07ppq?,y
public class FileAccessI implements Serializable{ %6M%PR~u
!Ow M-t
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9~K+h/
RandomAccessFile oSavedFile; 6vJS"+ <
long nPos; [+}0K{(O=
XJq]l6a:
jgkY^l
public FileAccessI() throws IOException SVV-zz]3M
{ /~+Fzz
this("",0); 0Q cJ Ek
} nI+.De~
@|'9nPern
kKC] n
public FileAccessI(String sName,long nPos) throws IOException EgzdRB\Cf
{ {sq:vu@NC
oSavedFile = new RandomAccessFile(sName,"rw"); -G=.3 bux
this.nPos = nPos; Y2g%{keo
oSavedFile.seek(nPos); *F(<:3;2
} ZHoYnp-~z
,&Zk63V
U2Ky4UFm
public synchronized int write(byte[] b,int nStart,int nLen) %y)hYLOJ
{ >f|0# *
int n = -1; {5+69&:G.
try{ O%&N6U
oSavedFile.write(b,nStart,nLen); $"0`2C
n = nLen; 1$m{)Io2(
} 2) 2:KX
catch(IOException e) c<Q*g
{ 7c@5tCcC-
e.printStackTrace (); :kjs: 6f]
} <l+hcYam
cVmF'g
I0^oaccM
return n; u:wijkx
} xKepZ
sY]pszjT
[~n|ROo
} Sj8fo^K50
87+u`~
Dx9k%G)!
/* Zu2 $$_+L
**SiteInfoBean.java *Rc?rMF!
*/ 5.kKg=a
package NetFox; rQTG-& ,
iI*qx+>f?
7|!Zx-}
public class SiteInfoBean { #TeAw<2U
'I2[}>mj2
``rYzj_
private String sSiteURL; //Site's URL <0jM07\<
private String sFilePath; //Saved File's Path AthR|I|8
private String sFileName; //Saved File's Name Ch~y;C&e+r
private int nSplitter; //Count of Splited Downloading File [V5,1dmkI
yv)-QIC3
/7-FVqDx8
public SiteInfoBean() `)BZk[64
{//nSplitter的缺省值为5 9wdX#=I
//default value of nSplitter is 5 t0^)Q$
this("","","",5); _u~`RlA
} sLK$H|%>m
*WWDwY@!u
JX{rum
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0 r;tI"
{ 2B_+5
sSiteURL= sURL; }me`(zp
sFilePath = sPath; ]^@m $O
sFileName = sName; PevT`\>
this.nSplitter = nSpiltter; VZ9`Kbu
vsYbR3O
_m%Ab3iT~
} 9.6ni1a'
)2:U]d%pk
6/Z_r0^O
public String getSSiteURL() Scmew
{ /-=h|A#Kh
return sSiteURL; V.ae 5@;
} HisH\z/i5)
UHIXy#+o5
91k-os(4]
public void setSSiteURL(String value) h6tYy_(G
{ tC7 4=
sSiteURL = value; =>GGeEL
} 9*r l7
e8z?) 4T
<DEu]-'>
public String getSFilePath() $bZ5@)E
{ 8N4E~*>C
return sFilePath; 3i9~'j;F3
} jgfr_"@A
e&Z ?I2J
A3.pz6iT>
public void setSFilePath(String value) `t g=__D
{ aZo>3z;
sFilePath = value; QS-X_
} 0P;LH3sx
Nlu]f-i':
t^~itlE{
public String getSFileName() r[2*K 9
{ sAF="uB
return sFileName; T?7++mcA
} t\n'Kuk`
2>Qy*
[X@JH6U r
public void setSFileName(String value) DJ!pZUO{
{ jk%H+<FU`
sFileName = value; k<rJm P{
} : TqeVf
X*&Thmee
FbW$H]C$
public int getNSplitter() ;i?R+T
{ iD>H{1 h
return nSplitter; NpS =_QeNw
} <J.q[fd1*
(Hs,Tj
'GLpSWL+*
public void setNSplitter(int nCount) 6Z@T /"mU(
{ \[wbJ
nSplitter = nCount; Ghar hJ>v
} d8p5a C+E
} =(v'8?--
zV"'-iP
<." @H<-`*
/* &@D\4b,?nm
**Utility.java m'uFj !
*/ "@Qg]#]JH
package NetFox; !=6\70lJ
v:NQrN
q/qig5Ou
public class Utility { h)z2#qfc
#E_<}o
#+|0o-
public Utility() U/h@Q\~U
{ STPRC&7;
Lw<.QMN%f
Y6(=cm
} 1L=)93,M
hOuHTo^
//线程睡眠 gE8>o:6)6:
public static void sleep(int nSecond) Qr?1\H:Lq
{ isFxo,R9r
try{ X-psao0tI`
Thread.sleep(nSecond); w`gT]Rn
} 6Q]JY,+
catch(Exception e) $|AasT5w
{ 0(o.[%Ye
e.printStackTrace (); XaMsIyhI
} pfFHuS~
} |ZOdfr4uW
9xFI%UOb#
//日志 t~8H~%T>v
public static void log(String sMsg) C3(h j
{ :Vw{ lB
System.err.println(sMsg); o3h>)4
} Q2* ~9QkU
\[ 4y
=uR3|U(.|u
public static void log(int sMsg) (]zi;
{ -oB=7+g
System.err.println(sMsg); @0 [^SU?
} S,vdd7Y
} rCb#E}
(D{J|
z:u)@>6D1
/* 0!tuUn
**TestMethod.java rU1Ri
*/ ACpecG
package NetFox; QuC_sFP10
8O[l[5u&
be?Bf^O>
public class TestMethod { 5gb:,+
uJ0Wb$%
`oM'H+
public TestMethod() "+Sq}WR
{ ///xx/weblogic60b2_win.exe _z9~\N/@[
try{ 1X9J[5|ll
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); XCO8A\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); vb}c)w dp?
SiteFileFetch fileFetch = new SiteFileFetch(bean); dEW= V"W
fileFetch.start(); mmy/YP)
} jINI<[v[
catch(Exception e){e.printStackTrace ();} )UyJ.!Fly
'6L@l
;WhRDmT
} %Hhk 6tR,
Ty7)j]b"zl
,qNbo 11
public static void main(String[] args) </aQ
{ "F4 3q8P
new TestMethod(); ?-8DS5
} h.NCG96S
} po.QM/b \
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