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)); 8d?r )/~
} jdiH9]&U
for(int i=0;i<nEndPos.length-1;i++) W4%I%&j
{ 7?9QlUO
nEndPos = nStartPos[i+1]; >gRb.-{ux
} zR_ "
nEndPos[nEndPos.length-1] = nFileLength; s!:'3[7+
} $Ypt /`
} A(V,qw8
n`8BE9h^
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//启动子线程 2Nrb}LH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /H/@7>
for(int i=0;i<nStartPos.length;i++) 4W5[1GE.
{ 84j6.\,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `|)V]<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), HL]8E}e\"
nStartPos,nEndPos,i); t6DgWKT6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Sg
fileSplitterFetch.start(); : E[\1
} BCMQ^hP}t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |J-Osi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); eS-akx^@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X [IVK~D}z
nEndPos = " + nFileLength); .)59*'0
// fileSplitterFetch[nPos.length-1].start(); ,P ~jO
'i+j;.
\NU^Jc_k7
//等待子线程结束 :%7y6V*
//int count = 0; T&+*dyNxMK
//是否结束while循环 PvF3a`&r
boolean breakWhile = false; !k@(}CN_*
GVR/p
3V=wW{;x
while(!bStop) ]s_,;PGU
{ iga.B
write_nPos(); ~ES6Qw`Oe
Utility.sleep(500); ywQ[>itMa
breakWhile = true; S9RH&/^H
GB,f'Afl
~+|Vzm|S}
for(int i=0;i<nStartPos.length;i++) yAD-sy +/
{ \GYrPf$
if(!fileSplitterFetch.bDownOver) gr1NcHu
{ #0$fZ
breakWhile = false; +lC?Vpi^
break; hhWIwR
} o|`[X'
} g?B4b7II
if(breakWhile) B0E`C
break; c(Ws3
?, B4
K Q^CiX
//count++; F3nYMf
//if(count>4) j/ [V<
// siteStop(); SG\6qE~
} *).u:>D4
=EFCd=i
v}\4/u
System.err.println("文件下载结束！"); _4,/uG|a O
} CCDU5l$$
catch(Exception e){e.printStackTrace ();} #mKF)W
} =T!eyGE
59Lc-JJ
p{|!LcSU$2
//获得文件长度 W_.WMbT
public long getFileSize() <qGxkV
{ Fz11/sKz
int nFileLength = -1; ?}g^/g !
try{ (yrN-M4~t
URL url = new URL(siteInfoBean.getSSiteURL()); :3b.`s(M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); boS=
httpConnection.setRequestProperty("User-Agent","NetFox"); A |u-VXQ
H46N!{<;@
6 &Lr/J76
int responseCode=httpConnection.getResponseCode(); Ef @
if(responseCode>=400) r)S:-wP
{ 0:I[;Qt
processErrorCode(responseCode); sGFvSW
return -2; //-2 represent access is error %>'Zy6C<j
} _=Z?5{7S>
`6y=ky.,
S5o,\wT
String sHeader; eWWqK9B.-
] M`%@ps
ylm #Xa
for(int i=1;;i++) 3 C{A
{ PI\C*_.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gFpub_
//Utility.log(in.readLine()); "?%2`*\
sHeader=httpConnection.getHeaderFieldKey(i); TB}6iIe
if(sHeader!=null) 'uC=xG.*}
{ W{m_yEOf
if(sHeader.equals("Content-Length")) Gsn$r(m{K
{ p<[MU4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ) >te|@}o
break; j)ME%17
} JR_%v=n~x
} !mZDukfjQ
else S86,m=
break; `L LS|S]
} \VpN:RI
} ZyM7)!+kPa
catch(IOException e){e.printStackTrace ();} %rlMjF'tG
catch(Exception e){e.printStackTrace ();} (/7b8)g
!He_f-eZ
.0YcB
Utility.log(nFileLength); a8$4
NX4G;+6
c=,HLHpFO(
return nFileLength; Al1_\vx7
} ]ur?i{S,
{p.^E5&
%nRgHN>
//保存下载信息（文件指针位置） 9>ajhFyOhX
private void write_nPos() ayI<-s-
{ %oB0@&!mS
try{ J#W*,%8O
output = new DataOutputStream(new FileOutputStream(tmpFile)); WeJ=]7T'L
output.writeInt(nStartPos.length); IwXWtVL
for(int i=0;i<nStartPos.length;i++) kXV;J$1
{ G2<$to~{
// output.writeLong(nPos); a,36FF~&
output.writeLong(fileSplitterFetch.nStartPos); IaZmN.k*
output.writeLong(fileSplitterFetch.nEndPos); L{&>,ww
} AJ+\Qs(0
output.close(); wBDHhXi0
} jG~-V<&
catch(IOException e){e.printStackTrace ();} :i4AkBNK
catch(Exception e){e.printStackTrace ();} 0K'{w]Q
} 5vFM0
$l2`@ia"
9a[1s|>w-
//读取保存的下载信息（文件指针位置） Qs '_\|/-
private void read_nPos() vw 6$v
{ cLEd-{x
try{ -4[eZ>$A|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4E2#krE%
int nCount = input.readInt(); Sg$\H
nStartPos = new long[nCount]; ?q7MbQw
nEndPos = new long[nCount]; Gphy8~eS
for(int i=0;i<nStartPos.length;i++) n}b{u@$
{ ^k*%`iQ
nStartPos = input.readLong(); [>N#61CV5
nEndPos = input.readLong(); lz!(OO,g
} 6cd!;Ca
input.close(); g$ HL::
} ?wu@+
catch(IOException e){e.printStackTrace ();} @0]w!q
catch(Exception e){e.printStackTrace ();} 2Z(t/Zp>
} X-tw)
)ut$644R
Ni8%K6]z
private void processErrorCode(int nErrorCode) (/At+MF3E
{ XD?Lu _.
System.err.println("Error Code : " + nErrorCode); BTD_j&+(
} X!:J1'FE
#]dq^B~~
gg.]\#3g
//停止文件下载 &#JYh=#
public void siteStop() <THwl/a
{ 6fo\z2
bStop = true; @ R[K8
for(int i=0;i<nStartPos.length;i++) `*cqT
fileSplitterFetch.splitterStop(); j85B{Mab&
FShUw+y
w[F})u]E
} v-N4&9)%9
} =/}Rnl+c
//负责部分文件的抓取 !uit
**FileSplitterFetch.java oKYa?
*/ 8o[gzW:Q)U
package NetFox; "n]x%. *
>;XtJJS
[ :)F-
import java.io.*; "f8,9@
import java.net.*; hP8w3gl_
^,YTQ.O
>-\^)z
public class FileSplitterFetch extends Thread { sBYDo{01
JN:L%If
@D=B5f@(o
String sURL; //File URL k>F!S`a&m
long nStartPos; //File Snippet Start Position 2Y%7.YX"
long nEndPos; //File Snippet End Position lX%-oRQ/os
int nThreadID; //Thread's ID sVr|kvn2
boolean bDownOver = false; //Downing is over +_/ys!
boolean bStop = false; //Stop identical L){V(*K '
FileAccessI fileAccessI = null; //File Access interface c]Gs{V]\
2z*}fkJ
@`)>-k
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gm pY[
{ `*[\b9>
this.sURL = sURL; jI'?7@32`
this.nStartPos = nStart; vmEn$`&2t
this.nEndPos = nEnd; 4lR+nmAZ
nThreadID = id; x]yIe&*('
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A9N8Hav
} oexTz[
YhNrg?nS
45n.%*,
public void run() )5n0P Zi
{ :!l.ze{F
while(nStartPos < nEndPos && !bStop) $W=)-X\>
{ vs$h&o>|
qLN\>Z,3;
h^_^)P+;
try{ hSxK*.W*3
URL url = new URL(sURL); Iila|,cM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2q]ZI
httpConnection.setRequestProperty("User-Agent","NetFox"); c7{s'ifG
String sProperty = "bytes="+nStartPos+"-"; ovOV&Zt
httpConnection.setRequestProperty("RANGE",sProperty); J~xm[^0
Utility.log(sProperty); `q\F C[W
mi$C%~]5m
A4|7^Ay
InputStream input = httpConnection.getInputStream(); 4[#)p}V
//logResponseHead(httpConnection); @67GVPcxl
Y'jgp Vt
9mp`LT
byte[] b = new byte[1024]; |=v,^uo
int nRead; %]Nm'"Y`U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -fV\JJ
{ ;hODzfNkS
nStartPos += fileAccessI.write(b,0,nRead); P`O`MwEAf
//if(nThreadID == 1) 8 e_]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pGD-K41O]
} $[b}r#P
f+ZOE?"
:R +BC2x
Utility.log("Thread " + nThreadID + " is over!"); FWU>WHX
bDownOver = true; 'v^shGI%Ht
//nPos = fileAccessI.write (b,0,nRead); wLiPkW
} _.R]K$U
catch(Exception e){e.printStackTrace ();} O-ENFA~E;v
} @YRy)+
} ?/1LueC:
]mi\Y"RO
cAGM|%
//打印回应的头信息 ^`M%g2x
public void logResponseHead(HttpURLConnection con) 6HJsIeQ
{ ;nL7Hizo,
for(int i=1;;i++) !]}C!dXd
{ j@#RfVx
String header=con.getHeaderFieldKey(i); y{<js!au
if(header!=null) 8@+<W%+th
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N-b'O`C
Utility.log(header+" : "+con.getHeaderField(header)); fj['M6+wd
else Cq7 uy
break; T%9t8?I
} ]l h=ZC
} ^i8biOSZu
rN7JJHV
)g?jHm-p\
public void splitterStop() & ^1 b]f
{ ;qy;;usa
bStop = true; k<j]b^jbz
} :-U&_%#w
@:B}QxC
A-.Wd7^~*
} Im-qGB0C
Z_dL@\#|
THX% z `
/* op2Zf?Bx{+
**FileAccess.java },}g](!m
*//文件访问(定位，写) t~dK\>L
package NetFox; x!W5'DO
import java.io.*; /&G|.Cx
ltU{P|7!E
yK9EHJ$
public class FileAccessI implements Serializable{ E_$nsM8?
~ArRD-_t
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a%a0/!U[
RandomAccessFile oSavedFile; >dgq2ok!u
long nPos; zsd<0^ p\{
_qk&W_u
\(=xc2
public FileAccessI() throws IOException G\5Bdo1g
{ of7p~{3H
this("",0); 6&6dd_K(
} {|OXiRm'
S76MY&Vx23
-Vb5d!(
public FileAccessI(String sName,long nPos) throws IOException W`oyDg,D
{ @`nG&U
oSavedFile = new RandomAccessFile(sName,"rw"); %dr*dA'
this.nPos = nPos; lTN^c?
oSavedFile.seek(nPos); 1ljcbD)T;
} _-#o[>2[
x $[_Hix
;.xKVH/@
public synchronized int write(byte[] b,int nStart,int nLen) {*g{9`
{ F4"bMN
int n = -1; d:vc)]M>f{
try{ `-cw[@uD
oSavedFile.write(b,nStart,nLen); x[)]u8^A
n = nLen; 9An\uH)mL
} U6wy^!_X9
catch(IOException e) ]Lg~I#/#
{ ZQir?1=
e.printStackTrace (); )K::WqR%w)
} O[L#|_BnEO
X7-[#} T
B]b/(Q+
return n; z0a`*3 -2
} }M"])B I
'qde#[VB
VM&Ref4
} Y}q~Km
hMvJNI6O
3m4 sh~
/* n"}*C|(k
**SiteInfoBean.java bUM4^m
*/ 5A5t
package NetFox; @e\ @EW
_\,lv \u
[h&s<<# D
public class SiteInfoBean { <tsexsw
i|,}y`C#
H"Hl~~U
private String sSiteURL; //Site's URL l=Jw6F+5
private String sFilePath; //Saved File's Path pV\>?
private String sFileName; //Saved File's Name Z-_Xt^N
private int nSplitter; //Count of Splited Downloading File .!lLj1?p
,!,M'<?"
=oiz@Q@H
public SiteInfoBean() y0?HZ Xq
{//nSplitter的缺省值为5 (|<+yQ,@>
//default value of nSplitter is 5 cH:&S=>h
this("","","",5); kz("LI]
} pXBh^
agruS'c g
`(P71T
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) x;} 25A|
{ _(~E8g
sSiteURL= sURL; 0Y0`$
sFilePath = sPath; nra)t|m
sFileName = sName; -k2|`t _
this.nSplitter = nSpiltter; ?|}qT05
7h41E#
9B83HV4J
} (JjxrZ+L
]BRwJ2< x
:9x]5;ma
public String getSSiteURL() *uccY_
{ 2~ETu&R:
return sSiteURL; 7PUy`H,&
} cH|J
7i02M~*uS
8I#^qr5
public void setSSiteURL(String value) Y,,Z47% E
{ O7.eq524
sSiteURL = value; _/.VXW
} +7 j/.R
Lc]hwMGR*
+!nf?5;
public String getSFilePath() <HS{A$]
{ Vu4LC&q
return sFilePath; ePaC8sd0
} eOXu^M>:F
:=!6w
q;f L@L@-
public void setSFilePath(String value) 'gD./|Z0
{ H.]<fvP
sFilePath = value; \LQZoD?W
} %Q.M& U
RF -c`C
/n$R-Q
public String getSFileName() P%Q'w
{ t.O~RE
return sFileName; d$E>bo-\
} 5 /oW/2"
#u\~AO?h
z-"P raP
public void setSFileName(String value) Hv:~)h$
{ ^u0y<kItX
sFileName = value; -=UvOzw
} K9VP@[zbJ
UMFM.GI
a~JZc<ze
public int getNSplitter() v/$<#2|
{ U%#Vz-r
return nSplitter; 4&e<Sc64
} maQxU(
g_>E5z.
n? =O@yq
public void setNSplitter(int nCount) cf"!U+x
{ ,Tx38
nSplitter = nCount; )u]=^
} ]+w 27!
} jG}nOI
f8f3[O!x
If'N0^'W
/* 1E4`&?
**Utility.java GN5*
*/ %=s2>vv9
package NetFox; [x`),3qD
E0!0 uSg&
V}Q`dEk2r
public class Utility { k{|>!(Ax
h:FN&E c}
R]>0A3P
public Utility() d:cOdm>,
{ GlJOb|WOX
Dd, &a
XI`s M~'
} Y(T$k9%}+
GGZ9DC\{
//线程睡眠 .]<gm9l
public static void sleep(int nSecond) x1Gc|K/-
{ Y q|OX<i`K
try{ AxO.adQE%
Thread.sleep(nSecond); qzZ;{>_f
} oGbh*
catch(Exception e) 8W7ET@`
{ dg+"G|nr
e.printStackTrace (); X%;4G^%ZI
} dEX67rUj;
} 5dX0C
c0X1})q$
//日志 c2s73iz
public static void log(String sMsg) o(D_ /]'8
{ q8R,#\T*
System.err.println(sMsg); 'fzJw
} zpNt[F?~1
]'>jw#|h
Go]y{9+(7
public static void log(int sMsg) ew c:-2Y^
{ oJE<}~_k
System.err.println(sMsg); N>sHT =_
} !# xi^I
} ye}86{l
J~ *>pp#U
"/taatcH
/* B~O<?@]d
**TestMethod.java *N6sxFs
*/ P.^*K:5@
package NetFox; =dWqB&
Vy=+G~
7MKZ*f@x;
public class TestMethod { -y$<fu9 e
)hVn/*mH
o?#-Tkb
public TestMethod() n%QWs1 b
{ ///xx/weblogic60b2_win.exe K&-uW_0
try{ 0juP"v$C>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QV#HN"F/K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]\ZmK0q<:
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,,S 2>X*L
fileFetch.start(); :#N]s
} T/hz23nH
catch(Exception e){e.printStackTrace ();} #.,LWL]
$L]M3$\9
usi3z9P>n
} #nj;F'O](
z\WyL;
*d 4A3|
public static void main(String[] args) @j(2tJ,w
{ G6\`Iy68/v
new TestMethod(); W}Rzn
} UMPW<>z
} x4?g>v*J
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