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)); RE*SdazY?
} #^eviF8
for(int i=0;i<nEndPos.length-1;i++) Dpof~o,f
{ T"dEa-O
nEndPos = nStartPos[i+1]; ^Ji5)c
} ,c7 8O8|
nEndPos[nEndPos.length-1] = nFileLength; rt."P20T
} Z!ub`coV[
} & }}o9
,H.q%!{h_
q5QYp
//启动子线程 e&wWlB![
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v_oNM5w
for(int i=0;i<nStartPos.length;i++) #Ok*Or
{ *xt3mv/<z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OHH wcJ7N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -,p(PK
nStartPos,nEndPos,i); \]o#tYN\a0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yyBy|7QgO
fileSplitterFetch.start(); :;]6\/ky
} QZzi4[-as
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N|8TE7- F|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O[q {y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +e4o~p
nEndPos = " + nFileLength); 7zy6`OP
// fileSplitterFetch[nPos.length-1].start(); bl:.D~@
jYuH zf
&grT}
//等待子线程结束 -4"E]f
//int count = 0; Oi=kL{DG:s
//是否结束while循环 VBsS1!g
boolean breakWhile = false; O~w&4F;{
Rsqb<+7
ULAAY$o@5
while(!bStop) 7X1T9'jI2
{ Xgc@cwd
write_nPos(); qifX7AXHr
Utility.sleep(500); -Vw,9VCF
breakWhile = true; ,GGr@})
?!8M I,c/
r1xNU0A
for(int i=0;i<nStartPos.length;i++) V[Auw3)
{ NtSa#$A
if(!fileSplitterFetch.bDownOver) #(!>
{ lcyan
breakWhile = false; vMDV%E S1t
break; <+pwGKtD
} l *.#g
} gHA"O@HgDI
if(breakWhile) >STWt>s
break; @)|62Dv /
|%we@ E
r#3(;N{=
//count++; =K}5 fe
//if(count>4) IIs'm!"Y>
// siteStop(); WHMt$W}%
} KK}^E_v
i5q VQo
wjQu3 ,Cj
System.err.println("文件下载结束！"); hH|3s-o
} j:\MrYt0H
catch(Exception e){e.printStackTrace ();} i\2~yXw\
} Z6A*9m
"\)j=MI8u+
&8z`]mB{t
//获得文件长度 n<uF9N<
public long getFileSize() 4tof[n3us
{ z45ImItH
int nFileLength = -1; $9j\sZj&
try{ ; Sq_DP1W
URL url = new URL(siteInfoBean.getSSiteURL()); &}Cm9V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (n|PLi
httpConnection.setRequestProperty("User-Agent","NetFox"); (%YFcE)SRS
seB ^o}
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int responseCode=httpConnection.getResponseCode(); v&D^N9hy9
if(responseCode>=400) tc.R(F96
{ 5ZSV)$t
processErrorCode(responseCode); u-$(TyDEl|
return -2; //-2 represent access is error vzd1:'^t
} $&I##od
S{zi8Oc6
:4;ZO~eq!
String sHeader; Cpz'6F^oP
D({%FQ"
}v"X.fa^
for(int i=1;;i++) OV_Y`u7YR
{ C%9;~S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "FwbhD0Gb
//Utility.log(in.readLine()); JUt 7
sHeader=httpConnection.getHeaderFieldKey(i); |^[]Oy=
if(sHeader!=null) 2I* 7?`
{ Q &<:W4N*
if(sHeader.equals("Content-Length")) O=?WI
{ J 6D?$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D4$;jz,,
break; ?<STt 9
} 4#1[i|:M
} -1;BwlL
else !X[b 4p
break; 6*J`2U9Q
} 3pl/kT.\
} !ZJ"lm
catch(IOException e){e.printStackTrace ();} B\G?dmo
catch(Exception e){e.printStackTrace ();} }_vE lBh6$
BxS\"W
vd6Y'Zk|F6
Utility.log(nFileLength); 0GK<l
<Wn={1Ts"
7F!_gj p
return nFileLength; xT6&;,|`
} yl0&|Ub
y-w=4_W
,]+P#eXgE
//保存下载信息（文件指针位置） nlOM4fJ(
private void write_nPos() 1JMEniB+9
{ p%pM3<p
try{ 8D@H4O.
output = new DataOutputStream(new FileOutputStream(tmpFile)); }RowAGWL
output.writeInt(nStartPos.length); Soy!)c]
for(int i=0;i<nStartPos.length;i++) }OZp[V
{ 9~2}hXm;
// output.writeLong(nPos); aVNBF`
output.writeLong(fileSplitterFetch.nStartPos); DK;p6_tT
output.writeLong(fileSplitterFetch.nEndPos); {4SwCN /
} $6e&sDJ
output.close(); tpOMKh.`
} h,o/(GNnW
catch(IOException e){e.printStackTrace ();} +[Cdd{2
catch(Exception e){e.printStackTrace ();} PeT _Ty
} WDQtj$e+
e=ZwhRP
QWz5iM
//读取保存的下载信息（文件指针位置） 3NAU|//J
private void read_nPos() K(@QKRZ7[
{ ]wFKXZeK
try{ 41Bp^R}^/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hqrI%%
int nCount = input.readInt(); "h?;)Ye
nStartPos = new long[nCount]; #2l6'gWE0
nEndPos = new long[nCount]; &9X`tCnL
for(int i=0;i<nStartPos.length;i++) _yk} [x0>
{ |TM&:4D]^
nStartPos = input.readLong(); hp=TWt~
nEndPos = input.readLong(); b Lag&c)
} 9DcUx-
input.close(); f0H 5 )DJf
} jm9J-%?
catch(IOException e){e.printStackTrace ();} WvSh i=
catch(Exception e){e.printStackTrace ();} W _j`'WN/
} 2ED^uc: 0S
{];4
JA0$Fz
private void processErrorCode(int nErrorCode) 0s)B~
{ EXn$ [K;
System.err.println("Error Code : " + nErrorCode); ~3-2Iu^F
} E/ %S0
0w^\sf%s
zWvG];fsN
//停止文件下载 CY2DxP%
public void siteStop() 'A@[a_
{ s!S,;H
bStop = true; F%QZe*m[
for(int i=0;i<nStartPos.length;i++) clfi)-^{K
fileSplitterFetch.splitterStop(); d.y2`wT
&X0/7)*"v
Cr0 \7
} JmN,:bI
} Vlb L p;
//负责部分文件的抓取 pl62mp!
**FileSplitterFetch.java <Q\`2{
*/ S,AZrgh,"X
package NetFox; O,qR$#l
ABhza|
xx;'WL,g
import java.io.*; !nVX .m9
import java.net.*; z('93vsO
R$,`}@VqZ3
k`)LO`))
public class FileSplitterFetch extends Thread { LDV{#5J
[$[t.m
~R)w 9uq
String sURL; //File URL EUuMSDp
long nStartPos; //File Snippet Start Position Zz?+,-$_*&
long nEndPos; //File Snippet End Position ?2EzNNcS
int nThreadID; //Thread's ID ~ezCE4^&
boolean bDownOver = false; //Downing is over 9U}EVpD
boolean bStop = false; //Stop identical 7C2/^x P
FileAccessI fileAccessI = null; //File Access interface }T,E$vsx
73}k[e7e
t1C{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException L$jyeFB5
{ \ vJ*3H6
this.sURL = sURL; G#@<bg3
this.nStartPos = nStart; g1zqh,
this.nEndPos = nEnd; :L`z~/6
nThreadID = id; (OG@]|-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 svo^#V~h'
} Q ;k_q3
APc@1="#J
;4qalxzu
public void run() Q^39Wk@
{ :He:Bdk
while(nStartPos < nEndPos && !bStop) 9(X *[X#
{ .{x5(bi0S
!h4So4p
;=^WIC+Nr
try{ =u;q98r
URL url = new URL(sURL); ;F0A\5I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i-ogeR?
httpConnection.setRequestProperty("User-Agent","NetFox"); / TJTu_#
String sProperty = "bytes="+nStartPos+"-"; W\KZFrV@
httpConnection.setRequestProperty("RANGE",sProperty); @~N#)L^
Utility.log(sProperty); R>0ta Q
QM_~w\
rW6w1
InputStream input = httpConnection.getInputStream(); iTK1I0
//logResponseHead(httpConnection); g)p[A 4
D3HB`{
Hd2_Cg FB
byte[] b = new byte[1024]; G:&Q)_
int nRead; ;zJ_apZ:{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ix/uV)]k`
{ eBN>|mE4N
nStartPos += fileAccessI.write(b,0,nRead); &WRoNc
//if(nThreadID == 1) vcSS+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )eG&"3kFe!
} 2'}2r ~6
oz0-'_
6/n;u{|
Utility.log("Thread " + nThreadID + " is over!"); 1%:A9%O)t
bDownOver = true; 4C[gW
//nPos = fileAccessI.write (b,0,nRead); i)p__Is
} D2mB4
catch(Exception e){e.printStackTrace ();} =1JRu[&]8
} Bh.'%[',
} c~C W-%wN
]fc:CR
}9kq?
//打印回应的头信息 JU6np4
public void logResponseHead(HttpURLConnection con) . =5Jpo
{ e8#3Y+Tc
for(int i=1;;i++) sg y
{ &ar}6eO
String header=con.getHeaderFieldKey(i); K_xOY *
if(header!=null) ]aR4U`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); sDC RL%0QK
Utility.log(header+" : "+con.getHeaderField(header)); :Ry24X
else }:irjeI,
break; b(VU{cf2d
} &Y>u2OZ
} vqHJc2yYkZ
vOS0E^
O o:jP6r
public void splitterStop() E6gEP0b
{ n\YxRs7 hF
bStop = true; bi[l,
} *X #e
{|%O)fr,
]4yvTP3[Rm
} (D{}1sZBQ
5HN<*u%z
85 hYYB0v
/* 7y\g~?5N
**FileAccess.java 8iNAs#s
*//文件访问(定位，写) "=(;l3-o
package NetFox; 57>ne)51
import java.io.*; [ lW "M
%},gE[N!J
g@k9w{_
public class FileAccessI implements Serializable{ lo:~~l
c5R{Sl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yh:,[<q
RandomAccessFile oSavedFile; Z]f2&
long nPos; A&F4;>dms
Y zS*p~|
q#`^EqtUF
public FileAccessI() throws IOException <T[N.mB
{ O| ]Ped9
this("",0); W6T&hB
} Ol[gck|~
o}A #-
ea0tx3'
public FileAccessI(String sName,long nPos) throws IOException zIFL?8!H9{
{ N -]PK%*
oSavedFile = new RandomAccessFile(sName,"rw"); .}N^AO=
this.nPos = nPos; ;vdgF
oSavedFile.seek(nPos); sCQup^\
} oNZW#<K
[{F7Pc
!@{[I:5
public synchronized int write(byte[] b,int nStart,int nLen) SZ{cno1`
{ H>f{3S-%
int n = -1; )yW_O:
try{ hhAC@EGG
oSavedFile.write(b,nStart,nLen); 2H[aY%1T
n = nLen; "}p?pF<'0
} )c/y07er
catch(IOException e) +3>/,w(x
{ ~iZF~PQ1_
e.printStackTrace (); acY[?L_6J
} p0y?GNQ
:QV6z*#zD
[9om"'
return n; ,jsx]U/^
} 7 afA'.=
' u};z:t
g/Jj]X#r
} YwWTv
ws>Iyw.u
[KI`e
/* hX| UE
**SiteInfoBean.java h) PB
*/ w9<FX>@
package NetFox; 3dDQz#
B4Af
RK:sQWG
public class SiteInfoBean { 8sF0]J[g{
ku9FN
7TPLVa=hO
private String sSiteURL; //Site's URL R 4QwWSBJ
private String sFilePath; //Saved File's Path Po!JgcJ#\
private String sFileName; //Saved File's Name , gr&s+
private int nSplitter; //Count of Splited Downloading File mRnzP[7-\)
F"f}vl
%802H%+
public SiteInfoBean() h9w^7MbO
{//nSplitter的缺省值为5 1\J1yOL
//default value of nSplitter is 5 ~uZLe\>K
this("","","",5); ~K#_'Ldrd
} x*"pDI0k)
NT9- j#V
-5,y 1_M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l)PFzIz=V
{ VBsFT2XiL
sSiteURL= sURL; (9 z.IH7}k
sFilePath = sPath; HD8"=7zJk
sFileName = sName; '"fU2M<.
this.nSplitter = nSpiltter; \ [^) WQ
9k+&fyy
Iam-'S5
} z'}=A
tqwk?[y}+l
[FV=@NI
public String getSSiteURL() < J<;?%]
{ c>WpOZ,
return sSiteURL; ~iR!3+yg4
} qqt.nrQ^
W/ZahPPq
-2jBs-z
public void setSSiteURL(String value) ;'Vipj
{ q~' K9
sSiteURL = value; u388Wj
} QOh w
hzuMTKH9
>upXt?
public String getSFilePath() N4` 9TN7
{ $6&GAJe
return sFilePath; G_,t\
} mp+\!
",aT<lw.
8T.5Mhx0jS
public void setSFilePath(String value) x+*L5$;h
{ &DbGyV8d"|
sFilePath = value; <GT>s
} 5nxS+`Pn.)
r@ T-Hi
DvRA2(M
public String getSFileName() Nvx)H(8F
{ DtJTnvG~B
return sFileName; %M;_(jda
} Z*vpQBbu
9?l?G GmQ
O2'bNR
public void setSFileName(String value) Q&.IlVB[
{ =@1R ozt
sFileName = value; 9OQ0Yc!3
} .XLV:6
u.pKK
S4{Mu(^xT
public int getNSplitter() '!yS72{$2
{ n$OE~YwP{
return nSplitter; Kixr6\
} "3Xv%U9@
)ZgER[
C$'D]fX
public void setNSplitter(int nCount) a$xeiy9
{ MKVfy:g%So
nSplitter = nCount; [ n0##/
} dxkRk#mf:
} q2S!m6!
6HEqm>Yau
m<FWv2)^
/* j*eUF-J1
**Utility.java ?2?S[\@`0U
*/ &sZ9$s:(^
package NetFox; x!"SD3r=4>
]< s\V-y
=.qm8+
public class Utility { cD'HQ3+
LL= Z$U $
J8u{K.(*7
public Utility() `?zg3GD_
{ Z{,GZT
E'e8&3!bx
fr}1_0DDz
} PJxak3
VxkCK02k
//线程睡眠 ZR;8rZ](
public static void sleep(int nSecond) M#\ <
{ C%}]"0Q1
try{ &dhcKO<4
Thread.sleep(nSecond); %YcxC0S[
} 3d*&':
catch(Exception e) | ((1V^
{ T~i%j@Q.6
e.printStackTrace (); 74@lo-/LY
} &v5G92
} r/NSD$-n
[x2JFS#4
//日志 ^CZCZ,v
public static void log(String sMsg) d5@X#3Hd
{ ADv^eJJ|
System.err.println(sMsg); DS#cm3
} K3vseor
v229H<
_ztZ>'
public static void log(int sMsg) ,op]-CY5
{ g>2aIun_Q
System.err.println(sMsg); 0dgP
} b]!9eV$
} G(U9rJ9
lLb:f6N
@s_3 0+
/* Ds%9cp*6
**TestMethod.java Tub1Sv>J
*/ "w}-?:# j
package NetFox; f4]N0
403[oOj
YBb)/ZghY
public class TestMethod { #O2wyG)oU
vU=9ydAj?
"$XYIuT
public TestMethod() 2v0!` &?M{
{ ///xx/weblogic60b2_win.exe ~I{EE[F>qL
try{ 9T(L"9r-e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); XDPL;(?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `I5O4|K)
SiteFileFetch fileFetch = new SiteFileFetch(bean); Tbv/wJ
fileFetch.start(); ShQ|{P9
} ' |&>/dyq
catch(Exception e){e.printStackTrace ();} "-w^D!C
rRB~=J"
\HAJ\9*w)
} sX+`wc
T4mv%zzS
q@(1Yivk
public static void main(String[] args) q[7CPE0n
{ 9<yAQ?7L
new TestMethod(); 0,HqE='w
} RFw(]o,9cR
} Z&_y0W=t
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