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)); hlvK5Z
} &.)^ %Tp\z
for(int i=0;i<nEndPos.length-1;i++) >;aWz%-
{ z3{G9Np
nEndPos = nStartPos[i+1]; n:I,PS0H<
} wv>^0\o
nEndPos[nEndPos.length-1] = nFileLength; htO+z7
} ,a{P4Bq
} ;IvY^(YS@;
7JD' )
?8H8O %Z8
//启动子线程 ?um;s-x)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]!W=^!
for(int i=0;i<nStartPos.length;i++) ihhDOmUto
{ %OL$57Ia
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^&9zw\x;z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Hs;4lSyUO
nStartPos,nEndPos,i); ^ glri$m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %vn"{3y>rF
fileSplitterFetch.start(); p;`>e>$
} j1Y~_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L Tm2G4+]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !,_u)4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hIYNhZv
nEndPos = " + nFileLength); y1jCg%'H
// fileSplitterFetch[nPos.length-1].start(); )W,aN)1)
5zK4Fraf
@(EAq<5{
//等待子线程结束 1SQ3-WUs
//int count = 0; h6L&\~pf
//是否结束while循环 t4."/.=+
boolean breakWhile = false; 9R!atPz9
1fp?
F$y$'Rzu_B
while(!bStop) NR$3%0 nC6
{ W 8<&gh+
write_nPos(); Co9^OF-k
Utility.sleep(500); H5/6TX72N
breakWhile = true; ]#iigPZ7
@o].He@L<j
B-RjMxX4>
for(int i=0;i<nStartPos.length;i++) `P@<3]
{ Y,qI@n<
if(!fileSplitterFetch.bDownOver) hk;5w{t}}
{ v4a8}G
breakWhile = false; E<rp7~#
break; ;}I:\P
} |MTnH/|
} 2"v6 >b%
if(breakWhile) >>4qJ%bL
break; sU<Wnz\[
}`@vF|2L
M5LfRBO
//count++; ~gJwW+
//if(count>4) [Q~#82hBhY
// siteStop(); C#.->\
} dohA0
#H&|*lr
xJpA0_xfG
System.err.println("文件下载结束！"); pHGYQ;:L
} C$=%!wf
catch(Exception e){e.printStackTrace ();} ]6,\r"
} O0x,lq
SBu"3ym
4!{KWL`A
//获得文件长度 Ot0ap$&
public long getFileSize() n1ZbRV
{ (!u~CZ;
int nFileLength = -1; ^cC,.Fdw
try{ ^'MT0j
URL url = new URL(siteInfoBean.getSSiteURL()); c1(RuP:S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .|KyNBn
httpConnection.setRequestProperty("User-Agent","NetFox"); BiLY(1,
kM l+yli3c
(Bb5?fw
int responseCode=httpConnection.getResponseCode(); EmWn%eMN
if(responseCode>=400) 6D;Sgc5"
{ G6Axs1a
processErrorCode(responseCode); fivw~z|[@
return -2; //-2 represent access is error zy?|ODM
} 3)wN))VBX
b<[Or^X ]
*uRBzO}
String sHeader; k!j5tsiR
)bL'[h
0@0w+&*"@
for(int i=1;;i++) dmtr*pM_
{ =osk+uzzG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tPWLg),
//Utility.log(in.readLine()); &GO}|W
sHeader=httpConnection.getHeaderFieldKey(i); jxJ8(sr$
if(sHeader!=null) >{n,L6_t
{ ,$L4dF3
if(sHeader.equals("Content-Length")) IxN9&xa
{ |)th1 UH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *\a4wZ6<3
break; ah$b[\#C
} un"Gozmt5
} bn&TF3b
else "m$##X\
break; IZ-1c1
} tyDU @M
} h|9L5
catch(IOException e){e.printStackTrace ();} RZ?jJm$
catch(Exception e){e.printStackTrace ();} nIf1sH>
8P\G}
Pl06:g2I
Utility.log(nFileLength); se2!N:|R!G
bjW]bRw
V*;(kEqj
return nFileLength; GT.,
} np^N8$i:n
ea2ayT
r EE1sy/#
//保存下载信息（文件指针位置） K=Z|/Kkh
private void write_nPos() )gUR@V>e2
{ %g$o/A$
try{ \A#41
output = new DataOutputStream(new FileOutputStream(tmpFile)); {%5eMyF#
output.writeInt(nStartPos.length); ?3`UbN:
for(int i=0;i<nStartPos.length;i++) :K,i\
{ T@B/xAq5!
// output.writeLong(nPos); /N10
output.writeLong(fileSplitterFetch.nStartPos); k/_ 59@)
output.writeLong(fileSplitterFetch.nEndPos); dh iuI|?@
} E?f-wQF
output.close(); l}|%5.5-
} 9!\B6=r y4
catch(IOException e){e.printStackTrace ();} !X#OOqPr=
catch(Exception e){e.printStackTrace ();} OX7M8cmc+
} Yx%Hs5}8
a$OE0zn`
X=&ET)8-Y
//读取保存的下载信息（文件指针位置） e2TiBTbQaF
private void read_nPos() 9d659iC
{ ^98~U\ar
try{ Tn e4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wH&!W~M
int nCount = input.readInt(); ORw,)l
nStartPos = new long[nCount]; DU'`ewLL7
nEndPos = new long[nCount]; CAWNDl4
for(int i=0;i<nStartPos.length;i++) BoWg0*5xb
{ (k.[GfCbD
nStartPos = input.readLong(); 1N-\j0au
nEndPos = input.readLong(); `5.'_3
} z'n:@E
input.close(); ql{OETn#
} |v%YQ R
catch(IOException e){e.printStackTrace ();} %)W2H^
catch(Exception e){e.printStackTrace ();} &)ChQZA
} :Yh+>c}N
UKvWJnz
g-bK|6?yz
private void processErrorCode(int nErrorCode) 4N3R|
{ j{A y\n(
System.err.println("Error Code : " + nErrorCode); $k%2J9O
} 7(8;to6(
%s|Ely)
X`>i&I]
//停止文件下载 E6ElNgL
public void siteStop() cp7=epho
{ n M*%o-
bStop = true; }2.`N%[
for(int i=0;i<nStartPos.length;i++) /nNN,hz
fileSplitterFetch.splitterStop(); J=I:CD%
PiIpnoM
Vn}0}Jz
} K7:)nv E
} -;m0R
//负责部分文件的抓取 )9`qG:b'
**FileSplitterFetch.java l<LI7Z]A
*/ AJ`h9%B
package NetFox; ;:g@zAV
'Aq{UGN
06Sceq
import java.io.*; v%z=ysA
import java.net.*; ]Ie 0S~
J @1!Oq>
[D4SW#
public class FileSplitterFetch extends Thread { }rw8PZ9
6j]0R*B7`Q
]MitOkX
String sURL; //File URL g7`LEF <A
long nStartPos; //File Snippet Start Position w``ST
long nEndPos; //File Snippet End Position <)c)%'v
int nThreadID; //Thread's ID 9IfmW^0
boolean bDownOver = false; //Downing is over ~KX/ Ai
boolean bStop = false; //Stop identical ??vLUv
FileAccessI fileAccessI = null; //File Access interface &.Qrs:U
'XjZ_ng
dOH&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k2tF}
{ @9RM9zK.q
this.sURL = sURL; )lqAD+9Q
this.nStartPos = nStart; #a,PZDaE
this.nEndPos = nEnd; bJ {'<J
nThreadID = id; 9-a0:bP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '$(^W@M#6
} E]n&=\
H3=qe I
s)D;a-F
public void run() +_oJ}KI
{ h]}wp;Z
while(nStartPos < nEndPos && !bStop) j-}O0~Jz
{ 29] G^f>
'4Bm;&6M
EUX\^c]n
try{ O;jrCB
URL url = new URL(sURL); (vJNHY M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yjJ5>cg
httpConnection.setRequestProperty("User-Agent","NetFox"); @:vwb\azVD
String sProperty = "bytes="+nStartPos+"-"; `kXs;T6&
httpConnection.setRequestProperty("RANGE",sProperty); ]Q3ADh
Utility.log(sProperty); %pL''R9VF
0znR0%~
_8UU'1d
InputStream input = httpConnection.getInputStream(); 'S&zCTX7j
//logResponseHead(httpConnection); 0pd'93C
16(QR-
p6Gy,C.
byte[] b = new byte[1024]; []1C$.5DD
int nRead; *P=VFP
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HBXOjr<,{
{ 3;{kJQ
nStartPos += fileAccessI.write(b,0,nRead); mNTzUoZF'@
//if(nThreadID == 1) ;'@9[N9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0=1T.4+=
} U$A]8NZ$S
^k">A:E2
#h ]g?*}OJ
Utility.log("Thread " + nThreadID + " is over!"); ?1 4{J]H4
bDownOver = true; K Z91-
//nPos = fileAccessI.write (b,0,nRead); n 0L^e
} S|N_o
catch(Exception e){e.printStackTrace ();} =X:Y,?
} E*K;H8}s
} )F]]m#`
zHRplm+i
+\ .Lp 5
//打印回应的头信息 jm/`iXnMf
public void logResponseHead(HttpURLConnection con) `1fY)d^ZS
{ >0TxUc_va
for(int i=1;;i++) 0 /U{p,r6`
{ Kis"L(C
String header=con.getHeaderFieldKey(i); h3 }OX{k
if(header!=null) I1M%J@Cz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lX4 x*
Utility.log(header+" : "+con.getHeaderField(header)); +iRh
else ENs&RZ;
break; t-bB>q#3>
} UySZbmP48
} VuZuS6~#J
g1"kTh
Dp-z[]})1
public void splitterStop() ]Q)OL
{ #.)0xfGW)n
bStop = true; RMu~l@
} <R=Zs[9M1
lzVq1@B
/t$d\b17pX
} {B*s{{[/'
R$[vm6T?
>!1-lfa8
/* vV-`jsq20H
**FileAccess.java n9ej7oj
*//文件访问(定位，写) Z,Dl` w
package NetFox; M!D3}JRm
import java.io.*; wjB:5~n50k
VTY 5]|;
RQ" ,3.R==
public class FileAccessI implements Serializable{ ?J~_R1Z
^o&. fQ*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Z o(rTCZX
RandomAccessFile oSavedFile; z5*'{t)
long nPos; u <v7;dF|s
BuXqd[;K%
M@v.c;Lt
public FileAccessI() throws IOException Ne1$ee.NE
{ Si;H0uPO
this("",0); MeZf*' J
} i5@z< \
*#+An<iT ;
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public FileAccessI(String sName,long nPos) throws IOException 3{sVVq5Y
{ T'Dv.h
oSavedFile = new RandomAccessFile(sName,"rw"); [2M'PT3
this.nPos = nPos; T%*D~=fQ'
oSavedFile.seek(nPos); ]2qo+yB
} uiR8,H9*M
DT&@^$?
U-tTW*[1]
public synchronized int write(byte[] b,int nStart,int nLen) }a(dyr`S
{ 0*{%=M
int n = -1; )|#sfHv7
try{ ,/|T-Ka
oSavedFile.write(b,nStart,nLen); m#\dSl}
n = nLen; bq0zxg%
} )irEM
catch(IOException e) 'YSHi\z ](
{ z9Rp`z&`E
e.printStackTrace (); 3eQ&F~S
} YNsJZnGr8#
p>8D;#HmL
0{-q#/
return n; NyNXP_8
} ' %o#q6O
:&."ttf=
"87:?v[[1
} =fFP5e ['
sdw(R#GE
=]0&i]z[.
/* Se =`N
**SiteInfoBean.java BR;D@R``}
*/ t'k$&l}+
package NetFox; 3AN/ H
I^$fMdT
smo~7;
public class SiteInfoBean { bY~pc\V:`w
'E""amIJ
oe-\ozJ0
private String sSiteURL; //Site's URL L) T (<
private String sFilePath; //Saved File's Path Qh\60f>0
private String sFileName; //Saved File's Name H6/$d
private int nSplitter; //Count of Splited Downloading File [S!/E4>['
d>qY{Fdz
'm kLCS
public SiteInfoBean() Qd3 j%(
{//nSplitter的缺省值为5 \LexR.Di
//default value of nSplitter is 5 c'yxWZEv
this("","","",5); C1 *v,i
} nZYBE030
/f;~X"!
t;\Y{`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) XU(eEnmom
{ 4@ai6,<
sSiteURL= sURL; Qq|57X)P*
sFilePath = sPath; FVJGL
sFileName = sName; k~w*W X'
this.nSplitter = nSpiltter; X45%e!
`3&v6
rmg}N
} 7J<5f)
QhJiB%M
8v%o,"
public String getSSiteURL() &^Q/,H~S
{ c\AfaK^KF
return sSiteURL; ;u)I\3`*!
} $*fMR,~t&
SO0PF|{\r
;uP:"k
public void setSSiteURL(String value) 20Wg=p9L
{ sd|).;s}
sSiteURL = value; 1p=]hC
} +QJ#2~pE
eehb1L2(b
5$C-9
public String getSFilePath() 11;MN
{ #AQV(;r7@
return sFilePath; A~70
} $qj2w"'
I b5rqU\
E~"y$Fqe
public void setSFilePath(String value) o?\?@H
{ /%io+94
sFilePath = value; C;^X[x%h7$
} ~Z'?LV<t
c{w2Gt!
qlPT Ll
public String getSFileName() 0LJv'
{ FU4L6n
return sFileName; f) L
} )lDD\J7
{"KMs[M
`<d }V2rdz
public void setSFileName(String value) R (n2A$
{ &Au@S$ij
sFileName = value; }k.Z~1y
} ncT&Gr
h<<v^+m
IW] rb/H
public int getNSplitter() aK^q_ghh[
{ "3Y0`&:D
return nSplitter; ey$&;1x#5
} 6.yu-xm
x7 ,5
p9-K_dw3X@
public void setNSplitter(int nCount) AFwdJte9e
{ uQKT
nSplitter = nCount; YPI-<vM~
} O0H.C0}
} z+X}HL
b@hqz!)l`
'!B&:X)
/* 5\VWCI
**Utility.java 7s^'d,P
*/ X 0+vXz{~g
package NetFox; {]4LULq
]3Sp W{=^(
q'Pf]
public class Utility { 7;@]t^d=$
/Lr.e%
+9sQZB# (
public Utility() [j+sC*
{ U8$27jq
sc#qwQ#
1 [Bk%G@D&
} 1T n}
?(_08O
//线程睡眠 QQc -Ya!v
public static void sleep(int nSecond) 1EX;MW-p<T
{ E}Uc7G
try{ *MW\^PR?
Thread.sleep(nSecond); >uEzw4w
} IO<6
catch(Exception e) ="l/klYV
{ b^vQpiz
e.printStackTrace (); )Hr`MB
} YKK*ER0
} &s!@29DXR
2=!RQv~%
//日志 Y"$xX8o
public static void log(String sMsg) uHRsFlw
{ !&@615Vtw
System.err.println(sMsg); 4 s9LB
} t\O16O7S
!^G\9"4A
}4X0epPp;:
public static void log(int sMsg) ]7c=PC
{ rEz^
System.err.println(sMsg); :NTO03F7v
} `N8O"UcoBo
} #}5uno
&_8947
}"%N4(Kd
/* M&M6;Ph
**TestMethod.java ~v6D#@%A
*/ |CbikE}kL
package NetFox; @BMx!r5kn
goWuw}?
\cM2k-
public class TestMethod { #fM`}Ij.A
P16~Qj
VuZr:-K/
public TestMethod() %E;'ln4h&,
{ ///xx/weblogic60b2_win.exe Z0r'S]fe
try{ yEy6]f+>+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \o3gKoL%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j.= 1rwPt
SiteFileFetch fileFetch = new SiteFileFetch(bean); <9b&<K:
fileFetch.start(); es0hm2HT3
} +jgSV.N
catch(Exception e){e.printStackTrace ();} hOK8(U0
n~Lt\K:
)D%~`,#pQ
} WUTowr
z`b,h\
7F.4Ga;
public static void main(String[] args) %A0/1{(
{ ql~J8G9
new TestMethod(); j_j]"ew)
} j B{8u&kz)
} >=w)x,0yX
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