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)); -TjYQ
} eLL>ThMyW
for(int i=0;i<nEndPos.length-1;i++) yL_-w/a
{ {ZY^tTsY
nEndPos = nStartPos[i+1]; $/Zsy6q:
} zf5s\w.4
nEndPos[nEndPos.length-1] = nFileLength; 0F0V JE
} 8Rc4+g
} I8 8y9sW
`jvIcu5c
f&7SivS#
//启动子线程 D2[uex
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )wCA8
for(int i=0;i<nStartPos.length;i++) FOM~Uj
{ @HMt}zD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :_p3nb[r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rcF;Lp :
nStartPos,nEndPos,i); 3k5Mty
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bxqXFy/I
fileSplitterFetch.start(); F2AM/m^!q
} <E&1HeP
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Iwize,J~X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9K Ih}Q@P
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pvDr&n9
nEndPos = " + nFileLength); NA]7qb%%<
// fileSplitterFetch[nPos.length-1].start(); [qIi_(%o
;]i&AAbj
RR75ke[Hs
//等待子线程结束 &!N5}N&
//int count = 0; )[~ #j6
//是否结束while循环 \#m;L/D
boolean breakWhile = false; `(_cR@\
&:S_ewJK7
N+"Y@X yg
while(!bStop) y@nWa\iG
{ |pqLwnOu
write_nPos(); VahR nD
Utility.sleep(500); o!aKeM~|Es
breakWhile = true; ~SUA.YuF
0u'4kF!P!
e\%QHoi>u
for(int i=0;i<nStartPos.length;i++) y~SFlv36
{ 7I&7YhFI
if(!fileSplitterFetch.bDownOver) {QM;%f
{ )>\J~{
breakWhile = false; &Sa<&2W4S
break; x +q"%9.c
} ~V`D@-VND
} 9RE{,mos2v
if(breakWhile) >#$(M5&}-
break; HvKueTQ
p<Ah50!B
p27A#Uu2}
//count++; i74^J+xk
//if(count>4) C$"jZcm,I
// siteStop(); v|?hc'Fj
} nxsQDw\hy
mB"zyL-
2^ ^;Q:
System.err.println("文件下载结束！"); P>)-uLc~W
} k]qZOO}
catch(Exception e){e.printStackTrace ();} ,au64sH
} 5caYA&R
N>/*)Frt
[YHvyfk~_
//获得文件长度 T 2x~fiM
public long getFileSize() eG"iJ%I
{ q&<#)#+
int nFileLength = -1; /quf'CV}
try{ :0CR=]WM
URL url = new URL(siteInfoBean.getSSiteURL()); R`76Ae`R8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d;mQ=k 1
httpConnection.setRequestProperty("User-Agent","NetFox"); p? iJ'K
c~5#)AXMT
N5}vy$t_P
int responseCode=httpConnection.getResponseCode(); \S=!la_T@m
if(responseCode>=400) 9(ZzwkD'>
{ htX'bA
processErrorCode(responseCode); 7v?tSob:b
return -2; //-2 represent access is error S82NU2L
} hX`WVVoF
MeQ(,irr^
,RCjfXa
String sHeader; \$?[>=<wB
)N)ziAy}
+(/XMx}a
for(int i=1;;i++) @!0j)5%
{ "sAR<5b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); thipfS
//Utility.log(in.readLine()); %f6l"~y
sHeader=httpConnection.getHeaderFieldKey(i); w?jmi~6
if(sHeader!=null) xXA$16kd
{ g~FB&U4c
if(sHeader.equals("Content-Length")) XhWMvme
{ l]sO[`X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4=o3ZRV
break; I;P?P5H
} z9w@-])
} yC+N18y?
else 2Mu-c:1
break; Ef%8+_
} iN`/pW/JE
} EOtrrfT&
catch(IOException e){e.printStackTrace ();} n 8AND0a1C
catch(Exception e){e.printStackTrace ();} u%XFFt5
@]3(l
*uA?}XEfi
Utility.log(nFileLength); <e/O"6='Z
g?`D8
II>X6
return nFileLength; Y0s^9?*
} y^;qT_)#
A'[A!NL%
:vurU$\
//保存下载信息（文件指针位置） JO :m: M
private void write_nPos() 3C_g)5 _:
{ rt^z#2$
try{ *ivbk /8
output = new DataOutputStream(new FileOutputStream(tmpFile)); Zr}`W\
output.writeInt(nStartPos.length); .8b4
for(int i=0;i<nStartPos.length;i++) *9PS2*n
{ m+OR W"o
// output.writeLong(nPos); $XyGCn
output.writeLong(fileSplitterFetch.nStartPos); wf|CE410
output.writeLong(fileSplitterFetch.nEndPos); !cSD9q*
} Vg:P@6s
output.close(); ^jf$V#z0/
} Dcus-,u~
catch(IOException e){e.printStackTrace ();} Y] P}7GZ
catch(Exception e){e.printStackTrace ();} /3KEX{'@U
} yA%[u.{
AQQj]7Y
JSGUl4N
//读取保存的下载信息（文件指针位置） g-+p(Ll|
private void read_nPos() N..9N$+(
{ ~RvU+D
try{ ya:H{#%6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); l' "<
int nCount = input.readInt(); Nz!AR$
nStartPos = new long[nCount]; f{3FoN=z
nEndPos = new long[nCount]; TUpEhQ+*
for(int i=0;i<nStartPos.length;i++) h(G&X9*
{ \GMudN
nStartPos = input.readLong(); /23v]HEPy
nEndPos = input.readLong(); dcHkb,HsO
} >$R-:>~zN
input.close(); jDXmre?
} 4?%0z) g
catch(IOException e){e.printStackTrace ();} tmb0zuJ&C!
catch(Exception e){e.printStackTrace ();} 5~rs55W
} $<ZX};/D
~gBqkZ# y?
lPFMNRt~8
private void processErrorCode(int nErrorCode) _I$]L8hC
{ <7PtC,74
System.err.println("Error Code : " + nErrorCode); *Gu=O|Mm
} l@j!j]nE
k?J}-+Bm[|
@F3d9t-
//停止文件下载 .S?,%4v%%
public void siteStop() }\gpO0Ox
{ mY`b|cS3p$
bStop = true; W]M[5p]*
for(int i=0;i<nStartPos.length;i++) @&EP& $*
fileSplitterFetch.splitterStop(); $7BD~U
!2{MWj
58v5Z$%--
} u[dI81`
} Q|xPm:
//负责部分文件的抓取 u"|.]r
**FileSplitterFetch.java pkk0?$l",
*/ niA{L:4
package NetFox; ~4\bR
7,+:QY@
|=h>3Z=r!
import java.io.*; `q xg
import java.net.*; As)-a5!
pbgCcO~xm
HuK'tU#
public class FileSplitterFetch extends Thread { =%]dk=n?TN
~&yaIuW<
x1Si&0T0P<
String sURL; //File URL ]h|GaHiE
long nStartPos; //File Snippet Start Position @NyCMe;]
long nEndPos; //File Snippet End Position [n:R]|^a
int nThreadID; //Thread's ID E3gQ`+wNg?
boolean bDownOver = false; //Downing is over wwpvmb
boolean bStop = false; //Stop identical Q0 ^?jh
FileAccessI fileAccessI = null; //File Access interface pkxW19h*0
#D>8\#53V/
|J6CH87>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4Yn*q~f
{ q-!m|<Z
this.sURL = sURL; dvXu?F55
this.nStartPos = nStart; lq%s/l
this.nEndPos = nEnd; #[i({1`^L
nThreadID = id; xknP `T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /\=g;o'
} _Y~+ #Vc
.79'c%3}
T %cN(0@
public void run() i^gzl_!
{ 2^:5aABQ
while(nStartPos < nEndPos && !bStop) 3F4I{L
{ |H |ewVUY
sXfx[)T<
9xWeVlfQ
try{ n=yFw\w'
URL url = new URL(sURL); `Y(/G"]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ChBZGuO:
httpConnection.setRequestProperty("User-Agent","NetFox"); XS1>ti|<
String sProperty = "bytes="+nStartPos+"-"; t=yM}#r$
httpConnection.setRequestProperty("RANGE",sProperty); BGA.8qWR4
Utility.log(sProperty); )P,jpE8
)D#*Q~
YL{LdM-xM
InputStream input = httpConnection.getInputStream(); '7E?|B0],
//logResponseHead(httpConnection); @,s[l1P
|9(uiWf
c5t?S@b
byte[] b = new byte[1024]; "0]i4d1l
int nRead; V= .'Db2D
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gGZ$}vX
{ GbMSO
nStartPos += fileAccessI.write(b,0,nRead); zx\?cF
//if(nThreadID == 1) jmAWto}.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l9SbuT$U
} J[<:-$E
\Mi y+<8$
9 s>JdAw?
Utility.log("Thread " + nThreadID + " is over!"); K\;b3
bDownOver = true; IJs`3?
//nPos = fileAccessI.write (b,0,nRead); 0_%u(?
} #^eviF8
catch(Exception e){e.printStackTrace ();} Dpof~o,f
} T"dEa-O
} paiF ah
,c7 8O8|
rt."P20T
//打印回应的头信息 Z!ub`coV[
public void logResponseHead(HttpURLConnection con) 0h#' 3z<
{ Gh@QR`xxc
for(int i=1;;i++) q5QYp
{ P+oZS
String header=con.getHeaderFieldKey(i); {E!$<A9
if(header!=null) z?+N3p9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A!hkofQ
Utility.log(header+" : "+con.getHeaderField(header)); DMf:u`<
else -,p(PK
break; \]o#tYN\a0
} yyBy|7QgO
} :;]6\/ky
QZzi4[-as
N|8TE7- F|
public void splitterStop() Ga~IOlS
{ P~=|R9t
bStop = true; D[9eu>"'9M
} ]X{LZYk
!R4`ihi1
]3C7guWz
} hPH=.rX
UX(#C,qgG
9r8*'.K`Z
/* Q7f\ 5QjT
**FileAccess.java gP)g_K(e
*//文件访问(定位，写) q*-q5FE
package NetFox; }}K44<]u
import java.io.*; dRt]9gIsx
}cMb0`oA
YB~}!F [(
public class FileAccessI implements Serializable{ rHh<_5-/>
llI`"a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `2UzJ~
RandomAccessFile oSavedFile; .3!=]=
long nPos; >H?8?a D
rT5dv3^MW!
>*dqFZF
public FileAccessI() throws IOException t|d9EC]c(
{ @ Al\:
this("",0); nIKh<ws4z
} ^P\(IDJCo
?r#e
jsc1B
public FileAccessI(String sName,long nPos) throws IOException .J'}qkz~
{ X >C*(/a
oSavedFile = new RandomAccessFile(sName,"rw"); fY$M**/,
this.nPos = nPos; jj.iW@m
oSavedFile.seek(nPos); !{"{(h)+@
} GuNzrKDr
8 <EE4y
~[isR|>
public synchronized int write(byte[] b,int nStart,int nLen) 05.^MU?^U
{ )"wWV{k
int n = -1; -+-@Yq$
try{ ^6oz3+
oSavedFile.write(b,nStart,nLen); CR&v z3\Q
n = nLen; -dZ7;n5&_
} .[NB"\<q
catch(IOException e) `/8Dmg
{ %fo+Y+t
e.printStackTrace (); U,~\}$<I
} !z$.Jcr1
JZ]4?_l
&}Cm9V
return n; 9v8{JaI3
} seB ^o}
a9`E&Q}z
v&D^N9hy9
} tc.R(F96
>7p?^*&7;
u-$(TyDEl|
/* vzd1:'^t
**SiteInfoBean.java d.3-@^P
*/ X@2[!%nm
package NetFox; I_oJx
Cpz'6F^oP
D({%FQ"
public class SiteInfoBean { #Huvn4x
:na9PW`TC
C%9;~S
private String sSiteURL; //Site's URL "FwbhD0Gb
private String sFilePath; //Saved File's Path JUt 7
private String sFileName; //Saved File's Name |^[]Oy=
private int nSplitter; //Count of Splited Downloading File 2I* 7?`
yn)K1f^
O=?WI
public SiteInfoBean() J 6D?$
{//nSplitter的缺省值为5 D4$;jz,,
//default value of nSplitter is 5 ?<STt 9
this("","","",5); 4#1[i|:M
} MuQyHEDF
uckag/tv
d<r=f"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !ZJ"lm
{ B\G?dmo
sSiteURL= sURL; }_vE lBh6$
sFilePath = sPath; vd6Y'Zk|F6
sFileName = sName; 0GK<l
this.nSplitter = nSpiltter; <Wn={1Ts"
7F!_gj p
zxTcjC)y
} yl0&|Ub
y-w=4_W
e C?adCb
public String getSSiteURL() 8*-8"It<"
{ tpwMy:<Ex
return sSiteURL; 7O^ySy"l
} -,C">T%\
]3uErnI
c=p`5sN)
public void setSSiteURL(String value) a;WRTV
{ $1y8gm
sSiteURL = value; B&ItA76
} $T.we+u
<csz4tL}P
BU(:6
public String getSFilePath() xb1 i{d
{ ?mU 3foa
return sFilePath; OOA%NKV
} 7p}J]!Z
CZe0kH^:{
e[.c^Hw
public void setSFilePath(String value) jT}3Zn
{ A[`c2v-hF
sFilePath = value; QV,X> !Nz
} 'Alt+O_
SR7$m<0t*
0*^ J;QGE
public String getSFileName() i`U:uwW`
{ C8 9c2
return sFileName; 1BO$xq
} ?^t"tY
Q\|72NWS
2#:/C:
public void setSFileName(String value) (C>FM8$J
{ 4=!SG4~o
sFileName = value; yr?*{;
} (N{Rda*8
3omFd#EP
"uf*?m3
public int getNSplitter() D!<[\G
{ [!H2i p-
return nSplitter; o=@0Bd8
} d$Y3 a^O|
t\Pn67t
^PA >t$
public void setNSplitter(int nCount) x(pq!+~K
{ |U)m'W-(q
nSplitter = nCount; G347&F)
} = }0M^F
} {5w'.Z]0v
v'gP,UO-%D
)[_A{#&
/* q/w<>u
**Utility.java Ja<pvb
*/ tl9=u-D13@
package NetFox; Mwp[?#1j
y"q7Gx*^j
,S[,F0"%
public class Utility { j}$dYbf$
WwG +Xa
jR-DH]@y
public Utility() &Uq++f6
{ o_;pEe
J%}9"Q5
<q|IP_
} Q M7z .
-wv5c
//线程睡眠 7.g)_W{7}
public static void sleep(int nSecond) X{KWBk.1
{ gSLwpIK%
try{ 5dOA^P@`,M
Thread.sleep(nSecond); %.^8&4$+
} Xb +)@Y4h
catch(Exception e) b[p<kMTir
{ ;ELQIHnD"
e.printStackTrace (); DwM4/m
} ZfalB
} U U!M/QJ
vQf'lEFk
//日志 FD>j\
public static void log(String sMsg) Zkl:^!*
{ u=^0n2ez
System.err.println(sMsg); $jMU|{
} eBiP\
l*]9
/LMb~Hy,
public static void log(int sMsg) $T* ##kyE9
{ 0=Jf93D5
System.err.println(sMsg); 2_Me 4
} ^ei[#I
} nTrfbK@
qZRx,^gd
04-phEA2Q
/* Cr0 \7
**TestMethod.java Y#'mALC2
*/ +<&\*VR
package NetFox; Vlb L p;
LL3RC6;e
G#n99X@-
public class TestMethod { `L0aQ$'>z
DDxNqVVt4
Zur7"OkQ
public TestMethod() &We1i&w
{ ///xx/weblogic60b2_win.exe u*_I7.}9
try{ UJ' +Z6d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g*$ 0G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bm1+|gssn
SiteFileFetch fileFetch = new SiteFileFetch(bean); cGSoAK
fileFetch.start(); +wd} '4)
} ]:TX> X!
catch(Exception e){e.printStackTrace ();} ),`MAevp
bqY}t. Y&"
L'=e /&
} xTQV?g J
,Ie~zZE&
*8k`m)h26
public static void main(String[] args) Dz,Fu:)
{ .N~qpynY
new TestMethod(); a(CZGIB
} p'{ `Uvr
} $t5 0<1
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