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)); :bI,rEW#_
} " xlJs93c
for(int i=0;i<nEndPos.length-1;i++) M.X}K7Z_/
{ lu3Q,W
nEndPos = nStartPos[i+1]; p?}&)Un
} t6j-?c('
nEndPos[nEndPos.length-1] = nFileLength; i:;$oT
} a!&bc8J7
} 4bE42c=Ca7
]bf'
4^0\dq
//启动子线程 xiEcEz'lk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y)IGTW o
for(int i=0;i<nStartPos.length;i++) a$A2IkD
{ xJ$Rs/9C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), haN"/C^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2lF WW(
nStartPos,nEndPos,i); aD0Q0C+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DZ,<Jmg&e*
fileSplitterFetch.start(); \ =S3 L<
} `d.Gw+Un
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F|9a}(-7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ca$y819E2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", x-tm[x@;o
nEndPos = " + nFileLength); u6]gQP">I
// fileSplitterFetch[nPos.length-1].start(); { 576+:*
PE^eP}O1
9+W!k^VWq
//等待子线程结束 RzMA\r;#
//int count = 0; P>>f{3e.
//是否结束while循环 y|$vtD%c
boolean breakWhile = false; m9 ^m
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CZF^Wxk
while(!bStop) 7?+5%7-
{ jQO*oq}
write_nPos(); 0kkRK*fp}x
Utility.sleep(500); u<$S>
breakWhile = true; /5&3WG&<u
E*Pz <
=`rppO
for(int i=0;i<nStartPos.length;i++) F@B
{ +Kxe ymwr2
if(!fileSplitterFetch.bDownOver) 6\%r6_.d
{ B>ms`|q=l
breakWhile = false; zw}@nqp
break; .i1jFwOd|G
} b0!*mrF]6
} M-{b
if(breakWhile) +ZY2a7uI
break; b5lk0jA
&8pCHGmV)
<)r,CiS
//count++; 0*/mc96
//if(count>4) (xI)"{
// siteStop(); <\B],M1=s=
} VaOpO8y`
AN|jFSQ'
Xw&QrTDS`
System.err.println("文件下载结束！"); zv8aV2?D
} r))$XM
catch(Exception e){e.printStackTrace ();} 6-)7:9y
} ;D%$Eh&oma
LsuAOB 8
Fr1;)WV
//获得文件长度 md1EJ1\14
public long getFileSize() 2tm~QL
{ #j(q/ T{x
int nFileLength = -1; tI/mE[W
try{ x.jYip
URL url = new URL(siteInfoBean.getSSiteURL()); MzBfHt'Rk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9^6|ta0;0
httpConnection.setRequestProperty("User-Agent","NetFox"); GN"M:L^k`
6ON
Q `J,dzY
int responseCode=httpConnection.getResponseCode(); L,s|gtv
if(responseCode>=400) QO1A976o
{ dSA [3V
processErrorCode(responseCode); WZ-4^WM=!
return -2; //-2 represent access is error DDqC}l_
} qat45O4A1
tJ(c<:zD
wgSR*d>y*9
String sHeader; $Uv<LVd(
]be0I)
gJ)h9e*m^
for(int i=1;;i++) 4~]8N@Bii
{ $@+p~)r(l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >Hd~Ca>
//Utility.log(in.readLine()); 0 .6X{kO
sHeader=httpConnection.getHeaderFieldKey(i); ,kGw;8X
if(sHeader!=null) N"q+UCRC
{ N}.Q%&6:
if(sHeader.equals("Content-Length")) sRo<4U0M;l
{ )A>U<n$h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Zi[{\7a
break; ,H#qgnp
} SK2J`*
} F^%{ ;
else ihpz}g
break; Z~-T0Ab-
} f)u*Q!BDD
} =jk-s*g
catch(IOException e){e.printStackTrace ();} <3],C)Zwc
catch(Exception e){e.printStackTrace ();} W<cW;mO
tk3<sr"IQ
Cu)%s
Utility.log(nFileLength); fl5UY$a2-
YW4bm
{WM&
return nFileLength; 3isXgp8
} .g(\B
Pq[0vZ_}dN
tF;& x g
//保存下载信息（文件指针位置） ,oBk>
private void write_nPos() 110>p
{ ~vjr;a(B
try{ .yFg$|yG
output = new DataOutputStream(new FileOutputStream(tmpFile)); M2zos(8g
output.writeInt(nStartPos.length); "c!oOaA
for(int i=0;i<nStartPos.length;i++) kMJQeo79
{ 3[|:sa8?s
// output.writeLong(nPos); ' q=NTP
output.writeLong(fileSplitterFetch.nStartPos); x3Dg%=R
output.writeLong(fileSplitterFetch.nEndPos); }v'PY/d.
} a@S4IoBg%
output.close(); #(26t _a
} ?hry=I(7r
catch(IOException e){e.printStackTrace ();} k^'d@1z;C
catch(Exception e){e.printStackTrace ();} gN!E*@7
} +hyWo]nW0
yp^[]Mz=
.JD4gF2N
//读取保存的下载信息（文件指针位置） mER8> <
private void read_nPos() P"~qio-
{ yuy+}]uB@
try{ \KnD"0KW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %Zv(gI`A
int nCount = input.readInt(); I 1VEm?CQ
nStartPos = new long[nCount]; "M5ro$qZ}
nEndPos = new long[nCount]; U~){$kpI#
for(int i=0;i<nStartPos.length;i++) l6}b{e
{ 6b+ WlIb
nStartPos = input.readLong(); Vgru, '
nEndPos = input.readLong(); _/z)&0DO
} _]?Dt%MkD
input.close(); G\,A> mT/P
} uz#eO|z@o
catch(IOException e){e.printStackTrace ();} ;*37ta
catch(Exception e){e.printStackTrace ();} Fy(nu-W
} u_[4n
tmY-m,U
!rsqr32]
private void processErrorCode(int nErrorCode) QE{;M
{ dPyBY]`
System.err.println("Error Code : " + nErrorCode); 1$3XKw'
} faL^=CAe
gQk#l\w_
~d#;r5>
//停止文件下载 Y+"hu2aPkY
public void siteStop() )o'U0rAx|a
{ &"H<+>`
bStop = true; x9o^9QJh
for(int i=0;i<nStartPos.length;i++) %9-#`
fileSplitterFetch.splitterStop(); @cTZ`bg
.^N#|hp^
OCOO02Wq1
} mb*h73{{
} p$b=r+1f
//负责部分文件的抓取 thm3JfQt
**FileSplitterFetch.java cJ(zidf_$
*/ 1R+)T'in
package NetFox; c^[1]'y
.5[LQR
!MF"e|W
import java.io.*; 2cX"#."5p
import java.net.*; Er)_[^) HG
yY@s(:
FOUs= E[
public class FileSplitterFetch extends Thread { <*(UvOQuX
oN6*WNtJ
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String sURL; //File URL B,m$ur#$
long nStartPos; //File Snippet Start Position }2!5#/^~
long nEndPos; //File Snippet End Position d;jJe0pH
int nThreadID; //Thread's ID zhvk%Y:
boolean bDownOver = false; //Downing is over TLL[F;uZ
boolean bStop = false; //Stop identical Lugk`NUvF
FileAccessI fileAccessI = null; //File Access interface Eztz~oFo
E_gDwWot
M;TfD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "JUQ)> !?
{ ]x(2}h^S
this.sURL = sURL; !K^Z5A_;
this.nStartPos = nStart; s*~jvL
this.nEndPos = nEnd; :Z]+Z_9p
nThreadID = id; )zLS,/pk^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f w>Gx9
} + x;ML
5N3!!FFE
HfeflGme*
public void run() I.\f0I'.
{ 2}#wdJ`
while(nStartPos < nEndPos && !bStop) feq6!k7
{ vhquHy.qi#
Q"K>ML>0
[]N$;~R7
try{ /HJ(Wt q
URL url = new URL(sURL); 4ysdna\+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I#hg(7|",
httpConnection.setRequestProperty("User-Agent","NetFox"); C=_-p"O#
String sProperty = "bytes="+nStartPos+"-"; :_YG/0%I
httpConnection.setRequestProperty("RANGE",sProperty); a$! {Tob2
Utility.log(sProperty); % x*Ec[l
=!P?/
Iv|WeSL.
InputStream input = httpConnection.getInputStream(); "KI,3g _V
//logResponseHead(httpConnection); 5@Lxbe( q
0)Um W{
n\ ',F
byte[] b = new byte[1024]; J)yy}[Fx
int nRead; GqD!W8+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Lvj5<4h;
{ m<'xlF
nStartPos += fileAccessI.write(b,0,nRead); W0T i ^@
//if(nThreadID == 1) <pl2 dxy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -S3+ h$Y8
} >8fz ?A
tDLk ZCP
Qx,$)|_
Utility.log("Thread " + nThreadID + " is over!"); 3(GrDO9^
bDownOver = true; yjFQk,A
//nPos = fileAccessI.write (b,0,nRead); 2:5gMt
} \^(vlcy
catch(Exception e){e.printStackTrace ();} >]Yha}6h
} A%w]~ chC9
} }:D~yEP
Z a1|fB
56 kgL;$h
//打印回应的头信息 FR6I+@ oX~
public void logResponseHead(HttpURLConnection con) ]%Yis=v
{ 5eSTT#[+R
for(int i=1;;i++) &@iF!D\u
{ @SG="L
String header=con.getHeaderFieldKey(i); 8\.1m9&r>o
if(header!=null) Oi[9b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); irw 7
Utility.log(header+" : "+con.getHeaderField(header)); <^q"31f
else =ObtD"
break; ~q|e];tA
} <W%Z_d&Xv
} xv%USm
)W6-h
:E&T}RN
public void splitterStop() MMr7,?,$
{ hYv 6-5_
bStop = true; <J}9.k
} |QTqa~~B
8EEQV}4
IS4K$Ac.
} W#\};P
Z#:@M[HH{
m'"VuH?^
/* 2CgIY89O
**FileAccess.java 6')SJ*|yS
*//文件访问(定位，写) @>nk^l
package NetFox; M-K@n$k
import java.io.*; KdMA58)
2xdJ(\JWM
{ro!OuA
public class FileAccessI implements Serializable{ 7`<? fO
aq\TO?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &r5%WRzpYT
RandomAccessFile oSavedFile; -x\l<\*
long nPos; [*ovYpj^
V//q$/&8(
j~f 7WJ
public FileAccessI() throws IOException `"mK\M
{ SWO!E
this("",0); Afhx`J1KO
} :XZom+>2n
R/cq00g
x Bw.M{
public FileAccessI(String sName,long nPos) throws IOException V+~{a:8[pq
{ |=}~>!!
oSavedFile = new RandomAccessFile(sName,"rw"); m:O2_%\l
this.nPos = nPos; I"<. h'
oSavedFile.seek(nPos); ]sP9!hup
} [#6Esy8|
F8;4Oj
s^R2jueR
public synchronized int write(byte[] b,int nStart,int nLen) E^W*'D
{ >P"/nS"nn
int n = -1; x2c*k$<p
try{ A?k,}~
oSavedFile.write(b,nStart,nLen); 'wlP`7&Tn
n = nLen; 7.rZ%1N
} J3S+| x h~
catch(IOException e) -?`l<y(
{ N_[ Q.HD"
e.printStackTrace (); w/W?/1P>q
} ~EkGG .
9+Bq00-Z$
58'y~Ou
return n; H>X1(sh#}
} 7tKft
sZBO_](S
g}r5ohqC#
} 3^yWpSC
Mf13@XEo
Ki;5 =)
/* QO1Gq9
**SiteInfoBean.java Riuv@i^6K
*/ '^3pF2lIw
package NetFox; q ? TI,
M|=$~@9#X
Nh/ArugP5P
public class SiteInfoBean { 9],"AjD
zR_l^NK
TEZqAR]G
private String sSiteURL; //Site's URL <[l}^`IC^4
private String sFilePath; //Saved File's Path ]JuB6o_L
private String sFileName; //Saved File's Name pFRnPOv
private int nSplitter; //Count of Splited Downloading File p&doQh
`z`;eR2oX
k r^#B^
public SiteInfoBean() n8aiGnd=v
{//nSplitter的缺省值为5 "dOY_@kg
//default value of nSplitter is 5 S9+gVR8]C
this("","","",5); F4(U~n<
} ,.MG&O
8>;o MM
Yx c >+mx
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3-%~{(T/
{ @soW f
sSiteURL= sURL; 3edK$B51;
sFilePath = sPath; Vzm7xl [
sFileName = sName; ZaindX{.1
this.nSplitter = nSpiltter; G)|HFcE
jF85bb$
5z]KkPQ
} =H?5fT^
oD1=}
HOb\Hn|6jq
public String getSSiteURL() d0E5;3tQ
{ ED&KJnquWJ
return sSiteURL; W\Y 4%y}
} q`zR6
PP|xIAc
n:kxG
public void setSSiteURL(String value) ~36XJ
{ uoc-qmm
sSiteURL = value; e}w!]
} fltcdA
u)>*U'bM
I@v.Hqg+7
public String getSFilePath() vB4qJ{f
{ 5X|aa>/
return sFilePath; |<icx8hbr
} vtjG&0GSK
,kuOaaV7K
>g=:01z9
public void setSFilePath(String value) sOenR6J<$
{ :PkSX*E[q
sFilePath = value; T5G+^XDA
} m':m`,c!
-8etH&
hV>Ey^Ty
public String getSFileName() ^E*C~;^S
{ )A;<'{t #L
return sFileName; f89<o#bm7h
} 36UWoo
Yb/^Qk59
||NCVGJG
public void setSFileName(String value) C.p*mO&N
{ w=2X[V}
sFileName = value; w`:KexD+
} .1M>KRSr,
uS.a9 Q(
'iK*#b8l
public int getNSplitter() JDlIf
{ `rLMMYD=
return nSplitter; e#{L~3
} 0C_Qp%Z
N?:S?p9R@
$%t
public void setNSplitter(int nCount) ]UTP~2N
{ /m:}rD
nSplitter = nCount; mAKi%)
} A(5? ci
} qpCi61lTDJ
JOk`emle
"5bk82."
/* V4D&&0&n
**Utility.java VNPdL
*/ _95tgJy
package NetFox; >48Y-w
hw2Hn
j+seJg<_
public class Utility { )qe o`4+y
1Btf)y'
qI:wm=
public Utility() :#;?dMkTY
{ ) 'KHUa9
" OtLJ
Dr609(zg^
} f}4h}Cq
hG]20n2
//线程睡眠 E}+A)7mA
public static void sleep(int nSecond) /@e\I0P^
{ I&0yUhn
try{ |n/id(R+
Thread.sleep(nSecond); 1??RX}8[L+
} !b=$FOC>
catch(Exception e) eS|p3jk;
{ -)GfSk
e.printStackTrace (); c$;enAf@
} "G:>}cs%?
} AS;{{^mM(
~XRr }z_Lq
//日志 suwj1qYJ4
public static void log(String sMsg) 7[\B{N9&W
{ `{":*V
System.err.println(sMsg); ufOaD7
} <j'#mUzd
`P~RG.HO
(;3jmdJhK
public static void log(int sMsg) U_?RN)>j
{ b04~z&Xv
System.err.println(sMsg); B~IOM
} wv$=0zF
} %;S5_K,
gg9W7%t/
}sZ]SE
/* /k,p]/e
**TestMethod.java tz{]H9
*/ ) AIZE?oX
package NetFox; /~Iy1L#
V !$m{)Y
i%iU_`
public class TestMethod { Ho/5e*X
sQvEUqy9
xXtDGP
public TestMethod() JC-L80-
{ ///xx/weblogic60b2_win.exe lbY>R@5
try{ |V&k1{V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Sn]A0J_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 01$SvLn:
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,LvJ'N
fileFetch.start(); <tNx*ce5
} jZGmTtx
catch(Exception e){e.printStackTrace ();} 9}-,dgAB
+qdK]RR}
j:#[voo7
} uIu0"pv`x
@`{UiTNX`
-3Ffk:
public static void main(String[] args) 7iJlW&W
{ Kh>^;`h
new TestMethod(); x;I*Ho
} O_033&
} V2*b f`/V
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