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)); "p/j; 6H
} /,MJq#@K
for(int i=0;i<nEndPos.length-1;i++) d~/q"r1"
{ JCPUM*g8
nEndPos = nStartPos[i+1]; t^xTFn
} z-@=+4~
nEndPos[nEndPos.length-1] = nFileLength; 3I!?e!y3(
} ^K7ic,{
} %.<H=!$
JOb*-q|y
26dUA~|KJ
//启动子线程 P+!"wX0*N
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |y h\
for(int i=0;i<nStartPos.length;i++) ) c/% NiN
{ < -uc."6\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'Q =7/dY3I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2+cNo9f
nStartPos,nEndPos,i); ik"sq}u_]E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l"q1?kaVg
fileSplitterFetch.start(); /erN;Oo%<
} Dy]I8_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >6~k9>nDb<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); RrhT'':[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OdQT2PA_
nEndPos = " + nFileLength); Qd_Y\PzS
// fileSplitterFetch[nPos.length-1].start(); .MVYB\6Q0
4EXB;[]
rUlS'L;$"
//等待子线程结束 KJ?y@Q
//int count = 0; mAeuw7Ni
//是否结束while循环 .fi/I
boolean breakWhile = false; CvPioi
( 7ws{)
^pS+/ZSi^
while(!bStop) !PMU O\y
{ &SAH2xR
write_nPos(); c(U
Utility.sleep(500); [w0/\]o
breakWhile = true; Z2Zq'3*
2[B4f7
SR^_cpZoi
for(int i=0;i<nStartPos.length;i++) kF{*(r=.o
{ &(zfa&j|
if(!fileSplitterFetch.bDownOver) aZet0?Qr
{ Aj9Ji"18za
breakWhile = false; x$wd O
break; ~"lJ'&J}
} v[TYc:L=
} ~1*A
if(breakWhile) `gpQW~*R-;
break; ExSO|g]%
Q \]Xm>
5tv<8~:K
//count++; 6CC&Z>
//if(count>4) -ZW3
// siteStop(); !Y<oN~<%)
} l;"Ab?P\
vBvNu<v7te
[EY`am8[
System.err.println("文件下载结束！"); nRb^<cZf
} c=[q(|+O!
catch(Exception e){e.printStackTrace ();} jJ3zF3Id
} 0@5E|<A
6yu]GK}es
"BKeot[""p
//获得文件长度 sVoW=4V8
public long getFileSize() :Pq.,s
{ 659v\51*
int nFileLength = -1; 8L5!T6+D&
try{ 3ta$L"a
URL url = new URL(siteInfoBean.getSSiteURL()); mPPk)qy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~=&t0D
httpConnection.setRequestProperty("User-Agent","NetFox"); 85IMdZ7I
]~>K\i
Ch_xyuJ
int responseCode=httpConnection.getResponseCode(); _P,^_%}V06
if(responseCode>=400) Te{ *6-gO3
{ BHj\G7,S
processErrorCode(responseCode); 6P`)%zj
return -2; //-2 represent access is error z *9FlV
} DjCx~@
.mL#6P!d3^
U@TjB
String sHeader; -$<O\5cAQ
~|Z'l%<Os
s?3i)Ymr
for(int i=1;;i++) Y-~~,Yl~
{ G{x[uE2X&f
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [9mL $;M W
//Utility.log(in.readLine()); @!Hr|k|
sHeader=httpConnection.getHeaderFieldKey(i); gVU1Y6.
if(sHeader!=null) `nJu?5
{ Y\+KoR';
if(sHeader.equals("Content-Length")) [m'CR 4(|
{ 2.Yi(r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); HFo-4"
break; p"`%
} u>.y:>
} 0nW F
else 7Bz*r0 9S
break; ~VTs:h
} Y7U&Q:5'
} 1;| LI?
catch(IOException e){e.printStackTrace ();} 2GWDEgI1o
catch(Exception e){e.printStackTrace ();} b^`AJK
*s)}Bj
Eff\Aq{
Utility.log(nFileLength); F6S~$<
4B-yTyO
r;iV$Rq!
return nFileLength; *(GZ^QH.
} 8v yG*UK
{UH9i'y:t
:DkAQ-<~
//保存下载信息（文件指针位置） ~fzuwz
private void write_nPos() dl l%4Sd
{ noNm^hFL
try{ q]<xMg#nu
output = new DataOutputStream(new FileOutputStream(tmpFile)); , fb( WY
output.writeInt(nStartPos.length); N dR ]
for(int i=0;i<nStartPos.length;i++) r$nkU4N'
{ h3Fo-]0
// output.writeLong(nPos); FA>1x*;c
output.writeLong(fileSplitterFetch.nStartPos); 6J%iZ
output.writeLong(fileSplitterFetch.nEndPos); en9en=n|
} _$/ +D:K
output.close(); IS]{}Y\3H
} gbOCR1PBg
catch(IOException e){e.printStackTrace ();} \gccQig1CJ
catch(Exception e){e.printStackTrace ();} }fIqH4bp
} ;vO@m!h}U
6~5$s1Yc
ARL
//读取保存的下载信息（文件指针位置） }uX|5&=~f
private void read_nPos() kI*UkM-
{ $V8vrT#:
try{ -!*p*3|03|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q e1oT)
int nCount = input.readInt(); #Ws53mT
nStartPos = new long[nCount]; 6E9N(kFYs
nEndPos = new long[nCount]; 5M?mYNQR/H
for(int i=0;i<nStartPos.length;i++) A['uD<4b
{ y7zkAXhJ
nStartPos = input.readLong(); IG.f=+<0
nEndPos = input.readLong(); 6 ,N6jaW
} M%=P)cC
input.close(); p/|(,)'+jx
} 2eok@1
catch(IOException e){e.printStackTrace ();} v@T'7?s.
catch(Exception e){e.printStackTrace ();} ]b[,LwB\`~
} rm+v(&
85>S"%_
p$!@I
private void processErrorCode(int nErrorCode) B.-A $/
{ 2mJ:c
System.err.println("Error Code : " + nErrorCode); c%<2z
} IUhp;iH
(iDBhC;/B
G8NRj9k?
//停止文件下载 zg]Drm
public void siteStop() Hbr^vYs5
{ ]G1R0 Q
bStop = true; mC(u2
for(int i=0;i<nStartPos.length;i++) hhq$g{+[
fileSplitterFetch.splitterStop(); nN{dORJlx
1 Nk1MGV
bf98B4<
} -h\@RC
} 'yT`ef
//负责部分文件的抓取 :{CFTc5:A
**FileSplitterFetch.java {'(ej5,6
*/ DJ:38_F
package NetFox; :Kay$r0+
:QA@ c|(PF
ec?1c&E
import java.io.*; \|{*arS
import java.net.*; 7t4v~'h;5e
w~v<v&
<;KRj85"j
public class FileSplitterFetch extends Thread { u[`v&e
iwz` x
M]0^ind
String sURL; //File URL nL;K|W
long nStartPos; //File Snippet Start Position XqFu(Lm8=
long nEndPos; //File Snippet End Position Rrz'(KSDw
int nThreadID; //Thread's ID 'oi2Seq
boolean bDownOver = false; //Downing is over M'|)dM|
boolean bStop = false; //Stop identical 5`UJouHi
FileAccessI fileAccessI = null; //File Access interface ;qVG \wQq
7ti<
;l`X!3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException lQr6;D}+
{ u% r!?-z
this.sURL = sURL; #efqG=q
this.nStartPos = nStart; %h3L
this.nEndPos = nEnd; k>$FT`
nThreadID = id; EI%M Azj}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =]WW'~
} @-}D7?
$8EV,9^U
91U^o8y
public void run() /kAwe *)
{ BQ5_s,VM
while(nStartPos < nEndPos && !bStop) b-,]A2.
{ zZ<ns+h
D l4d'&!
0P3j+? N%
try{ -??!@R7V
URL url = new URL(sURL); b1eK(F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^!$} BY
httpConnection.setRequestProperty("User-Agent","NetFox"); A8#.1uEgNb
String sProperty = "bytes="+nStartPos+"-"; /0Rt+`
httpConnection.setRequestProperty("RANGE",sProperty); d?Ia#K93G
Utility.log(sProperty); s+(l7xH$
%_]=i@Y~
3$MYS^D
InputStream input = httpConnection.getInputStream(); YG-Z.{d5Z
//logResponseHead(httpConnection); 9"[!EKW
wxH(&CB-{
-B<O_*wOj
byte[] b = new byte[1024]; DN4fP-m-
int nRead; E~rs11
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :5$xh
{ )[e%wPu4e
nStartPos += fileAccessI.write(b,0,nRead); ZTN:|IKT
//if(nThreadID == 1) y21)~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L7i}Ga!8
} 16a_GwfM
.vCY%0oE
=# k<Kw#
Utility.log("Thread " + nThreadID + " is over!"); deR$
bDownOver = true; L$oia)%t-
//nPos = fileAccessI.write (b,0,nRead); ;,Of\Efc|
} 5HWwl.D
catch(Exception e){e.printStackTrace ();} fF8a 1XV
} ?7fQ1/emhO
} <O <'1uO,
j;1~=j])
[]GthF
//打印回应的头信息 j CTQsV
public void logResponseHead(HttpURLConnection con) KK&<Vw|O\
{ ))%@@l[
for(int i=1;;i++) *#9VC)Q
{ |@T5$Xg]5
String header=con.getHeaderFieldKey(i); o(B<!ji~'
if(header!=null) s_S<gR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); NqQM!B]
Utility.log(header+" : "+con.getHeaderField(header)); ^8o_Iz)r,
else 2N8rM}?90
break; g:G%Ei~sF
} &4w\6IR
} V6DBKq
XgwMppacw
6Tm Rc
public void splitterStop() \;3B?8wbIl
{ `<l/GwtAJ
bStop = true; 2eZk3_w
} PfwI@%2
$V`KrA~]
W+F<P@[u<$
} m &0(%
0U>t>&,"
*`@XKK
/* %a)0?U
**FileAccess.java ::3iXk)
*//文件访问(定位，写) Q:-%3)g<<
package NetFox; 0?J|C6XM#4
import java.io.*; E<X{72fb>
)[@YHE5g
!s#'pTZk4
public class FileAccessI implements Serializable{ s2(w#n)
7yqSt)/U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2A@Y&g(6T7
RandomAccessFile oSavedFile; ain#_H
long nPos; @);!x41f
jkQt'!
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public FileAccessI() throws IOException [9db=$v8$
{ gL[1wM%?
this("",0); XEvGhy#
} <WQ<<s@#pb
avHD'zU}N
d'lr:=GQ
public FileAccessI(String sName,long nPos) throws IOException 7\\~xSXh
{ ex@,F,u>o
oSavedFile = new RandomAccessFile(sName,"rw"); E1U4v&P
this.nPos = nPos; A}t&-
oSavedFile.seek(nPos); .b_0k<M!p
} ]<\;d B
Q+u#?['
k *G!.
public synchronized int write(byte[] b,int nStart,int nLen) ]2aYi9)
{ `Q1WVd29
int n = -1; q{9X.-]}
try{ #Vn>ue+?
oSavedFile.write(b,nStart,nLen); Kc2OLz#
n = nLen; $ +GFOO
} @^y?Bh9jQ
catch(IOException e) }ZM*[j
{ EL 8N[]RF
e.printStackTrace (); [G'!`^V,
} [0tfY0
m>*A0&??[
E.H,1 {
return n; .@8m\
} XL.CJ5y>
Z}'F"}QI
1{hoO<CJ
} 90y9~.v
z 1#0
/]MB6E7&
/* V. bH$@ej
**SiteInfoBean.java !UgUXN*
*/ gvTOCF
package NetFox; iX>!ju'V
O%fp;Y{`
TsFdy{/o*
public class SiteInfoBean { z[KN^2YS
+GYI2
guUr1Ij
private String sSiteURL; //Site's URL xT=kxyu
private String sFilePath; //Saved File's Path eF8aB?&"
private String sFileName; //Saved File's Name z|DA _dG
private int nSplitter; //Count of Splited Downloading File cyHaku+
WFeMr%Zqh>
${I@YSU
public SiteInfoBean() RaM#@D7
{//nSplitter的缺省值为5 >Xh(`^}SQ*
//default value of nSplitter is 5 )-6s7
this("","","",5); '4^V4i
} _;J9q}X
a7v[l04
lM|WOmD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @7HOL-i
{ fN"oa>X
sSiteURL= sURL; -'H+lrmv
sFilePath = sPath; Br ^rK}|l
sFileName = sName; !OZhfMVd
this.nSplitter = nSpiltter; ^ ]6 80h
~&[P` Z$
n?P 5pJ
} $?/Xk%d+
@)2V"FE4i
@R OY}CZ{/
public String getSSiteURL() 2YE]?!
{ WKrZTPD'm
return sSiteURL; X%9xuc
} Mly z><
lPFdQ8M
(15Yw9Mv
public void setSSiteURL(String value) YqY6\mo
{ >NOYa3
sSiteURL = value; hRy}G'0
} 'd.@4 9
oRbYna?J
MZP><Je&
public String getSFilePath() -g[*wN8
{ )[M<72
return sFilePath; *liPJ29C[
} 0h@%q;g
0)`lx9&h
#HnyE+tD
public void setSFilePath(String value) zIQc#F6\5
{ im?XXsH'
sFilePath = value; xu?QK6D:
} [A..<[
k>0cTBY&
55\X\> 0C7
public String getSFileName() _6-/S!7Y\
{ *UL|{_)c
return sFileName; ^qus `6
} CMG`'gT
r4NT`&`g?
2E;%=e
public void setSFileName(String value) ,^IZ[D>u)
{ Ae_ E;[mj
sFileName = value; ;gW|qb+#)j
} _PNU*E%s<
.j7|;Ag
DKIDLf
public int getNSplitter() v.r$]O
{ @H&Aj..
return nSplitter; b^Rg_,s
} F\-qXSA
?3KI}'}EM
jGI!}4_
public void setNSplitter(int nCount) =*Wl;PI'
{ XZp(Po:H
nSplitter = nCount; ( }JX ]-
} 22tY%Y9
} pPQ]#v
'O\K Wj{
Dvd.Q/f
/* a^Zn }R r
**Utility.java 4pA<s-
*/ !S(jT?'w
package NetFox; Bu!Gy8\
CoJaVLl
\,p)
public class Utility { +qsdA#2
h3@mN\=h'
n=rPFpRLF
public Utility() *%Gy-5hM
{ fM S-
0pkU1t~9
`;cKN)Xk
} A*\4C3a'%
'^Sa|WXq
//线程睡眠 oVC~RKA*
public static void sleep(int nSecond) b;soMilz
{ K3 ]hUe#
try{ %HYC-TF#
Thread.sleep(nSecond); I &{dan2
} ZP%^.wxC
catch(Exception e) 5^* d4[&+
{ X/gh>MJJ<
e.printStackTrace (); C8&)-v|
} @ULr)&9
} XHpoaHyx
Fzu"&&>0$
//日志 [gv2fqpP
public static void log(String sMsg) ;PS[VdV
{ dC,F?^
System.err.println(sMsg); uu#ALB Jm
} zKiKda%)
{Qw,L;R
IUu[`\b=
public static void log(int sMsg) w:N\]=Vh
{ &,)9cV /
System.err.println(sMsg); s/,St!A4!
} /}M@ @W
} f0wQn09
v`Sllv5bV
x]a>Q),
/* \n<N>j@3
**TestMethod.java IK%j+UB
*/ [xI@)5Xk
package NetFox; d(To)ly.
u1]5qtg"
^vG*8,^S=8
public class TestMethod { 8swj'SjX
2^UFP+Yw
1Ete;r%5=
public TestMethod() Pi+,y
{ ///xx/weblogic60b2_win.exe U4LOe}Ny
try{ d(v )SS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NsJUruN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :1.$7Wt
SiteFileFetch fileFetch = new SiteFileFetch(bean); /3+7a\|mKr
fileFetch.start(); ~"=nt@M]
} 5%4:)s{4|
catch(Exception e){e.printStackTrace ();} `?Y/:4
O 6A:0yM4
2!" N9Adt
} >mt<`s
:Z=A,G
EzG7RjW
public static void main(String[] args) #~p1\['|M
{ `+* Mr
new TestMethod(); pOS.`rSK
} C@Wm+E~;8
} Sm,%>
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