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)); `>$l2,
} {[FJkP2l
for(int i=0;i<nEndPos.length-1;i++) !%yd'"6Dl
{ q/\Hh9`
nEndPos = nStartPos[i+1]; Zv1/J}+
} |Q~5TL>b
nEndPos[nEndPos.length-1] = nFileLength; }2_i<4,L
} UXV>#U?
} =Cr F(wVO"
+QFY.>KH
vn=0=(
//启动子线程 GI*2*m!u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |/p2DU2
for(int i=0;i<nStartPos.length;i++) 0f|nI8,z
{ \wo'XF3:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +QVe -
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V4 Wn
nStartPos,nEndPos,i); 0--0+?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mMV-IL
fileSplitterFetch.start(); <</ Le%
} f<~S0[H
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H;eOrX{GT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @8GW?R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ns1@=f cO
nEndPos = " + nFileLength); L%O( I
// fileSplitterFetch[nPos.length-1].start(); :>otlI<0t
'gwh:8Xc
-nrfu)G
//等待子线程结束 ~/kx
//int count = 0; ? v2JuhRe
//是否结束while循环 _-g?6q
boolean breakWhile = false; /SZg34%
b:}+l;e52
]):kMRv
while(!bStop) CK+_T}+-
{ O(QJiS
write_nPos(); oVSq#I4
Utility.sleep(500); YV0K&d
breakWhile = true; Fps.Fhm
~'l.g^p bv
*6e 5T
for(int i=0;i<nStartPos.length;i++) w_!]_6%{b
{ cU'^ Ja?%
if(!fileSplitterFetch.bDownOver) (GdL(H#IL
{ %,M(-G5j;
breakWhile = false; M%8:
break; #I.Wmfz
} /P/S0
} R\wG3Oxol
if(breakWhile) p$cSES>r:
break; UE9r1g`z
M _z-~G
:2fz4n0{/
//count++; `cgSyRD]
//if(count>4) hD:$Sv/H
// siteStop(); oLXQ#{([
} jreY'y:
{ +%S{=j
A"@C }f
System.err.println("文件下载结束！"); ~\z\f}w
} \;>idbV
catch(Exception e){e.printStackTrace ();} jpCQ2XD:
} M/,jHG8v
'J`%[,@V
v&EHp{8Qd
//获得文件长度 ? h$>7|
public long getFileSize() 3wBc`vJ!
{ Uv06f+P(
int nFileLength = -1; +FoR;v)z=F
try{ J!:ss
URL url = new URL(siteInfoBean.getSSiteURL()); ega< {t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S/ Y1NH
httpConnection.setRequestProperty("User-Agent","NetFox"); 7='M&Za
:B<lDcFKJ
zA![c l>$
int responseCode=httpConnection.getResponseCode(); `q 4%
if(responseCode>=400) 5UwaBPj4
{ !=.5$/
processErrorCode(responseCode); @GYM4T
return -2; //-2 represent access is error LV&tu7c
} c4R6E~S
Pv`^#BX'
wK[xLf
String sHeader; Ve&(izIh
o(. PxcD
C`D5``4
for(int i=1;;i++) =^P<D&%q
{ a<[@p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ywf.,V
//Utility.log(in.readLine()); .! LOhZ
sHeader=httpConnection.getHeaderFieldKey(i); FxC@KZG
if(sHeader!=null) pbivddi2
{ h{]l?6`
if(sHeader.equals("Content-Length")) ?<Dinq
{ C,w$)x5kls
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `n7z+
break; M[0@3"}}
} aT#R#7<Eg
} H;<hmbN?d
else 'hL\xf{
break; f4zd(J
} & h9ji[
} X+{4,?04+
catch(IOException e){e.printStackTrace ();} Od'!v&
catch(Exception e){e.printStackTrace ();} 0 )#5_-%
/r|^Dc Nx
]7ROCJ;
Utility.log(nFileLength); :JSOj@s
S >uzW #
"j9,3yJT
return nFileLength; OFCOMM
} Warz"n]iC
'?_;s9)
i7})VDsZ
//保存下载信息（文件指针位置） rZZueYuXO
private void write_nPos() a[)in ,3
{ j3~:\H
try{ Tc@r#!.m
output = new DataOutputStream(new FileOutputStream(tmpFile)); @Q3aJ98)2
output.writeInt(nStartPos.length); X#(?V[F]
for(int i=0;i<nStartPos.length;i++) koC2bX
{ KLs%{'[7:
// output.writeLong(nPos); {y'c*NS
output.writeLong(fileSplitterFetch.nStartPos); cp2e,%o
output.writeLong(fileSplitterFetch.nEndPos); u|=_!$8
} ZYrXav<
output.close(); rU5gQq;
} ow ~(k5k:
catch(IOException e){e.printStackTrace ();} F`U%xn,
catch(Exception e){e.printStackTrace ();} D2~e@J(K
} kVQKP U
;]MHU/
]E88zWDY`
//读取保存的下载信息（文件指针位置） [z`U9J
private void read_nPos() o8RagSIo8
{ <r,l
try{ IR|AlIv
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ld4QhZia
int nCount = input.readInt(); gec<5Ewg
nStartPos = new long[nCount]; N9Yc\?_NU_
nEndPos = new long[nCount]; A--Hg-N|
for(int i=0;i<nStartPos.length;i++) h{yqNl
{ s6w</
nStartPos = input.readLong(); $TL~SVHj;{
nEndPos = input.readLong(); Nj qUUkc
} 91r#lDR
input.close(); L\5j"] }`
} LqPn$rZ|$
catch(IOException e){e.printStackTrace ();} !Z,h5u\.w
catch(Exception e){e.printStackTrace ();} ' V;cA$ $
} fC2e}WR
kp[+Iun?
l[l('-f
private void processErrorCode(int nErrorCode) IBC P6[
{ D(s[=$zua
System.err.println("Error Code : " + nErrorCode); 8k]'P*9ulz
} 'd^U!l
r@H<@Vuc
x;l\#x/<
//停止文件下载 y|nMCkuX
public void siteStop() 1[a;2xA~
{ <jQ?l%\
bStop = true; ;-lk#D?n9
for(int i=0;i<nStartPos.length;i++) Z'>Xn^
fileSplitterFetch.splitterStop(); j\("d4n%C
+y>D3I
0~H(GG$VH
} AM1J ^Dp
} ^vLHs=<
//负责部分文件的抓取 N't*eCi
**FileSplitterFetch.java Mje6Q
*/ O$E3ry+?
package NetFox; 9l@VxX68M
<K%qaf
3lqR(Hh3
import java.io.*; mZDrvTI'
import java.net.*; 0iinr:=u
4T`u?T]
l&(,$RmYp
public class FileSplitterFetch extends Thread { =4"D8UaHr
@|6n.'f+
4iBp!k7
String sURL; //File URL G\?fWqx
long nStartPos; //File Snippet Start Position { ,/mQ3
long nEndPos; //File Snippet End Position 7@$Hua,GY
int nThreadID; //Thread's ID G)';ucs:,
boolean bDownOver = false; //Downing is over QDRSQ[\
boolean bStop = false; //Stop identical Gmi4ffIb3
FileAccessI fileAccessI = null; //File Access interface FRQ0tIp
3gaijVN
b-'41d}Hn
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WLQm|C,
{ K3$83%E
this.sURL = sURL; Pdmfn8I]%
this.nStartPos = nStart; &/d;4Eu
this.nEndPos = nEnd; 57Q^"sl
nThreadID = id; fD
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x1W<r)A )r
} -~~"}u
~&4Hc%*IB
YgNt>4K
public void run() p [4/Nq,c
{ >c*}Do{lG
while(nStartPos < nEndPos && !bStop) Cb7f-Eag
{ F=U3o=-:
8 sZ~3
X(U CN0#
try{ Fd":\7p
URL url = new URL(sURL); 8rAOs\ys
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cH?j@-pY
httpConnection.setRequestProperty("User-Agent","NetFox"); XZLo*C!MG
String sProperty = "bytes="+nStartPos+"-"; "jH=O(37
httpConnection.setRequestProperty("RANGE",sProperty); $NC1>83
Utility.log(sProperty); iUJqAi1o
eEePK~%c
;|6kFBGC"+
InputStream input = httpConnection.getInputStream(); 0tv"tA;
//logResponseHead(httpConnection); 1P:r=Rt/
i[/g&fx
T3,"g=
byte[] b = new byte[1024]; l)m\i_r:
int nRead; k3h,c;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) A9' [x7N
{ 4n @}X-)
nStartPos += fileAccessI.write(b,0,nRead); ;,![Lar5L
//if(nThreadID == 1) o?$kcI4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jFY6}WY)}7
} &Ed7|k]H
kRo dC(f @
m=<Tylv
Utility.log("Thread " + nThreadID + " is over!"); &^3KF0\Q
bDownOver = true; ="<5+G
//nPos = fileAccessI.write (b,0,nRead); ! /;@kXN
} mr dG-t(k
catch(Exception e){e.printStackTrace ();} kwU~kcM
} x%ju(B>
} _-eF &D
~G|un}g=
qq"&Bc>
//打印回应的头信息 S=H<5*]g
public void logResponseHead(HttpURLConnection con) WPi^;c8
{ 0g}+%5]yg
for(int i=1;;i++) .VG$`g"
{ -\6nT'P
String header=con.getHeaderFieldKey(i); MG)wVS<d_
if(header!=null) 9v>BP`Mg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Pw i6Ly`
Utility.log(header+" : "+con.getHeaderField(header)); eSo/1D
else }_93}e
break; _Mq0QQ42
} S`HshYlE q
} mL/]an@Y
$Y.Z>I;
2g5Ft
public void splitterStop() M\O6~UFq!
{ ^Yz.,!B[
bStop = true; k~f3~-"
} 0f~7n*XH
8}9|hT;
q}gj.@Q"
} n!=%MgF'*p
EN6a? }5
!T;*F%G9
/* 4|*b{Ni
**FileAccess.java +]Ca_`
*//文件访问(定位，写) $ZX^JWq
package NetFox; zy\p,
import java.io.*; ^% y<7>%
)D\cm7WX^[
"{>I5<:t
public class FileAccessI implements Serializable{ .BN~9w
fDyFkhc
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /*3[9,
RandomAccessFile oSavedFile; .3WDtVE
long nPos; qjcy{@ j
cpz'upVOZ
`L p3snS
public FileAccessI() throws IOException ~Wy&xs ZH
{ Trd/\tX#v&
this("",0); 3 $7TeqfAC
} 3=o^Vv
PZ5BtDm
ga0>J_
public FileAccessI(String sName,long nPos) throws IOException |Y'xtOMX
{ V_Z~$
oSavedFile = new RandomAccessFile(sName,"rw"); 86Q\G.h7
this.nPos = nPos; ?"MJ'u
oSavedFile.seek(nPos); "0x"Xw#I
} ?DPNa
xK4b(KJj
g-^Cf
public synchronized int write(byte[] b,int nStart,int nLen) vqh@)B+)
{ I)$`@.
int n = -1; K07SbL7g!p
try{ OiPE,sv
oSavedFile.write(b,nStart,nLen); &1O[N*$e
n = nLen; 4k'2FkDA
} gM=oH
catch(IOException e) A:Y]<jt
{ v4]7"7GuW
e.printStackTrace (); LL,&!KW[S
} &sbA:xZBA
fsc^8
l!Q |]-.@
return n; #fgRF
} hpJ[VKe
O[+![[N2
*O') {(
} S.o 9AUv9
Id8^6FLw
Hb&-pR@e\?
/* y- S]\tu
**SiteInfoBean.java AHsp:0Ma#
*/ PAF2=
package NetFox; |a@$KF$
#"|Y"#@k
uS :3Yo
public class SiteInfoBean { S-[]z*
nA8]/r1k
=\s(v-8
private String sSiteURL; //Site's URL _2{i}L
private String sFilePath; //Saved File's Path ;OW`(jC
private String sFileName; //Saved File's Name :b+C<Bp64r
private int nSplitter; //Count of Splited Downloading File @W3fKF9*R
5A]IiX4Z
G hH0-g{-
public SiteInfoBean() ]9z{ 95
{//nSplitter的缺省值为5 K~$o2a e
//default value of nSplitter is 5 n y6-_mA]
this("","","",5); (bH*i\W
} v ?@Ys+V
w?kdM1T
2d+IROA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,lm.~%}P*
{ ;zI;oY#.y
sSiteURL= sURL; W2h^ShG
sFilePath = sPath; qe!`LeT#
sFileName = sName; _$/(l4\T[
this.nSplitter = nSpiltter; C`OdMM>D
l= 5kd.{
4&/u1u0
} bG nBV7b
$5nOiaQL
*ie#9jA
public String getSSiteURL() ) ^PY-~o[
{ Gad!}dz
return sSiteURL; 7]a6dMh
} '/ 3..3k
Bt|S!tEy
u{=(]n
public void setSSiteURL(String value) ewB&PR
{ {>>ozB.
sSiteURL = value; 5o\yhYS:
} 04NI.Jv
@TC_XU)&
k{Yj!C> #
public String getSFilePath() Bn*D<<{T
{ 5{qFKo"g@,
return sFilePath; J!%Yy\G
} O?NAbxkp
LoUi Yf
\Oh9)X:I
public void setSFilePath(String value) ;hNnF&l
{ E,E:WuB
sFilePath = value; rFZB6A<(]
} Ac<V!v71
":?>6'*1
qJB9z0a<Ov
public String getSFileName() 0iqa]Am
{ YMLo~j4J
return sFileName; 3toY#!1Ch
} #B:J7&@fn
i%>]$*
K)$.0S9d
public void setSFileName(String value) MGX %U6
{ =K{$?%"
sFileName = value; *ghkw9/
} N!m-gymmF
b")&"o)G2W
Wcn3\v6_
public int getNSplitter() ?I)-ez
{ HY9H?T
return nSplitter; ovzIJbf
} 2#C!40j&\
hf0G-r_ow
U#1T HO`
public void setNSplitter(int nCount) dz&| 3o
{ K+Al8L?K_
nSplitter = nCount; g1muT.W]S
} eV^@kI4
} 7J./SBhB
cEi{+rfZd|
o %A4wEye
/* %l[Cm4
**Utility.java xZPSoxu
*/ `23&vGk}
package NetFox; 1F-o3\
Q[scmP^$^
Tz+2g&+
public class Utility { \bqNjlu
IyIh0B~i
Yi&;4vC
public Utility() NWNH)O@
{ v<_}Br2I[
UP 1Y3
D}vgXzD
} n_AW0i.
f( hK>H
//线程睡眠 ^i&/k
public static void sleep(int nSecond) SG |!wH^
{ :aLShxKA
try{ N+\#k*n?
Thread.sleep(nSecond); Q#urx^aw
} t= "EbPE
catch(Exception e) =t<!W
{ u!oHP
e.printStackTrace (); 7'7bIaJk
} 'IFbD["r
} RPPxiYU^
HcUivC
//日志 TgJx%
public static void log(String sMsg) $@Zb]gavt?
{ jWiZ!dtUZ
System.err.println(sMsg); 5*[zIKdt2
} 7on$}=%
F0o7XUt
k^z)Vu|f.
public static void log(int sMsg) V!3G\*$?
{ 'SYjEhvw
System.err.println(sMsg); IpGq_TU
} \r^=W=
} P9:7_Vc
hUSr1jlA
rl'YyO}2
/* RZjTUMAz4
**TestMethod.java ?JzLn,&
*/ ($7>\"+Tl
package NetFox; 5oGnPF
|Q`}a %
YNn,{Xi
public class TestMethod { SEr\ u#
{F6hx9?
J [2;&-@
public TestMethod() I"#jSazk
{ ///xx/weblogic60b2_win.exe 6|X
try{ $n(?oyf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g % q7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); GuQ3$B3j
SiteFileFetch fileFetch = new SiteFileFetch(bean); "^;'.~@e8
fileFetch.start(); ?Vbe
} f";70}_
catch(Exception e){e.printStackTrace ();} "}*P9-%
3lMmSKN
7`6n]4e
} L7G':oA_`p
1{_tV^3@
;Y?7|G97*S
public static void main(String[] args) h#^IT
{ +I/7eIG?|
new TestMethod(); *ls}r5k2Y
} _Z#yI/5r
} #lM!s
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