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)); xaVX@ 3r.3
} Kt*fQ `9
for(int i=0;i<nEndPos.length-1;i++) 3]?='Qq.(
{ aC2Vz9e
nEndPos = nStartPos[i+1]; 01-rBto$
} jFdgFKc)
nEndPos[nEndPos.length-1] = nFileLength; OP=brLGu0
} x}K|\KXy
} HJN GO[*g
1?H; c5?d&
NzyEsZ]$
//启动子线程 "=s}xAM|A
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pP":,8Q{
for(int i=0;i<nStartPos.length;i++) ^g6v#]&WA
{ KJoa^e;~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hbJy<e1W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =t-Ud^3
nStartPos,nEndPos,i); yg'CL/P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W`9{RZ'
fileSplitterFetch.start(); vw!7f|Pg ~
} gPB=Z!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,= ApnNUgX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S;#:~?dU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q;nAq%
nEndPos = " + nFileLength); 13/,^?
// fileSplitterFetch[nPos.length-1].start(); 4bGvkxZo`$
plB8iN`x<
wsB-( 0-
//等待子线程结束 {l$)X
//int count = 0; A4@z+ebb l
//是否结束while循环 Sy <E@1
boolean breakWhile = false; ty['yV-;a
`PtB2,?
dNf9,P_}
while(!bStop) :2c(.-[`
{ 6/L[`n"G
write_nPos(); 4h!yh2c..
Utility.sleep(500); A,EG0yb
breakWhile = true; 8Gy]nD
Uz_ob9l<#H
D.{vuftu
for(int i=0;i<nStartPos.length;i++) jW8ad{
{ 8/R$}b><
if(!fileSplitterFetch.bDownOver) P{K\}+9F
{ 5,MM`:{{
breakWhile = false; [rcM32
break; :!Q(v(M
} JJ)
} 4K:Aqqhds
if(breakWhile) Cj~e` VRhk
break; W895@
e"^WXP.t&
/'DAB**
//count++; +sn0bi/rG
//if(count>4) v2]N5
// siteStop(); OCdX'HN5Y
} ;U?=YSHk7
W#g!Usf:/
"B__a(
System.err.println("文件下载结束！"); }o!b3*#
} WP\kg\o
catch(Exception e){e.printStackTrace ();} ?E!M%c@,
} 7CR#\&h`
+pq=i
\\R<HuTY
//获得文件长度 W7|nc,i0\
public long getFileSize() _X?_|!;J
{ [^a7l$fmi
int nFileLength = -1; #B?lU"f8q^
try{ Adiw@q1&
URL url = new URL(siteInfoBean.getSSiteURL()); |qQ6>IZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C3=0st$
httpConnection.setRequestProperty("User-Agent","NetFox"); <Sd ef^
(kX:@9Pn
j-/$e,xX
int responseCode=httpConnection.getResponseCode(); uYlyU~M:D
if(responseCode>=400) m=h/A xW
{ !sI^Lh,Y
processErrorCode(responseCode); jt6_1^
return -2; //-2 represent access is error 9wfE^E1
} ?Mo)&,__
= =pQ V[
)g8Kicox5
String sHeader; ;>ml@@Z
b (HJ|
wGs'qL"z
for(int i=1;;i++) _M8'~$Sg
{ EVqqOp1$v4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); au=@]n#<(
//Utility.log(in.readLine()); W^HE1Dt]
sHeader=httpConnection.getHeaderFieldKey(i); 6X'0 T}
if(sHeader!=null) 7fWZ/;p
{ 8H};pu2
if(sHeader.equals("Content-Length")) e:MbMj6`
{ % mPv1$FH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'e<8j
break; FU*q9s`
} fS'` 9
} \ 6taC
else {l/`m.Z
break; ODRy
} 2H8\P+
} cna%;f.
catch(IOException e){e.printStackTrace ();} M).CyY;bm
catch(Exception e){e.printStackTrace ();} Zr6.Nw
g*_n|7pB
}vP(SF6
Utility.log(nFileLength); >@G"*le*)
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mIrN~)C4\
return nFileLength; FnOahLS
} >U\P^yU
1\lZ&KX$i
<ir]bQT
//保存下载信息（文件指针位置） By[M|4a
private void write_nPos() 5(1c?biP&
{ :>ca).cjac
try{ >*B59+1P
output = new DataOutputStream(new FileOutputStream(tmpFile)); +,7vbs3
output.writeInt(nStartPos.length); _I,GH{lhI
for(int i=0;i<nStartPos.length;i++) l%0-W
{ Y0Tw:1a
// output.writeLong(nPos); uTO%O}D N
output.writeLong(fileSplitterFetch.nStartPos); M;AvOk|&
output.writeLong(fileSplitterFetch.nEndPos); pIpdVKen
} M|@@ LJ'
output.close(); ]NW_oRH
} Hv' OO@z
catch(IOException e){e.printStackTrace ();} +S#Xm4
catch(Exception e){e.printStackTrace ();} #_3ZF"[zq
} /`#JM
{ktwX\z
SuI^8^f=
//读取保存的下载信息（文件指针位置） =%I;Y& K
private void read_nPos() -#4QY70H t
{ 3 Sf':N`u
try{ ;U a48pSv
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?Ec{%N%
int nCount = input.readInt(); 1x##b[LC
nStartPos = new long[nCount]; /Wl8Jf7'
nEndPos = new long[nCount]; rOYYZ)Qw
for(int i=0;i<nStartPos.length;i++) hZo f
{ 7#Fcn
nStartPos = input.readLong(); L|b[6[XTHL
nEndPos = input.readLong(); 2*gB~Jn4
} p,(W?.ZDN?
input.close(); c*R\fQd
} S5H}
catch(IOException e){e.printStackTrace ();} h~._R6y
catch(Exception e){e.printStackTrace ();} I;?PDhDb
} nHF~a?|FT
hVFZQJ?cv
211T}a
private void processErrorCode(int nErrorCode) I 5ZDP|
{ B=r+ m;(
System.err.println("Error Code : " + nErrorCode); |{,c2Ck:N
} TB<$9FCHK
Ne3YhCC>
K2v[_a~@
//停止文件下载 ?-0, x|ul
public void siteStop() E 8$S0u;`
{ d|W=_7z
bStop = true; ,E%O_:}R
for(int i=0;i<nStartPos.length;i++) {C8IYBm
fileSplitterFetch.splitterStop(); *].qm g%
j]-_kjt
>-3>Rjo>
} -V"W
} fb[lL7
//负责部分文件的抓取 Zrgv*
**FileSplitterFetch.java @1bl<27
*/ G%!i="/9
package NetFox; _2<UcC~
4Xwb`?}-
nHZhP4W
import java.io.*; U ){4W0
import java.net.*; 3=Uyt
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[yc7F0Aw
public class FileSplitterFetch extends Thread { =C|^C3HK
xwwL
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String sURL; //File URL b53s@7/mq
long nStartPos; //File Snippet Start Position :}#j-ZCC"
long nEndPos; //File Snippet End Position zyP/'X_~:
int nThreadID; //Thread's ID 7.)_H
boolean bDownOver = false; //Downing is over 3'0Jn6(
boolean bStop = false; //Stop identical tef>Py
FileAccessI fileAccessI = null; //File Access interface D=.Ob<m`Z
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException NweGK
{ im)r4={ 9
this.sURL = sURL; (WY9EJ<s,
this.nStartPos = nStart; v:w^$]4
this.nEndPos = nEnd; NMC0y|G
nThreadID = id; V_ntS&2o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =@hCc
} PJ<qqA`!
4? rEO(SZ
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public void run() |(,{&\
{ =Uo*-EH
while(nStartPos < nEndPos && !bStop) utn,`v
{ 3rJ LLYR
,I]]52+?4
tqpi{e
try{ 0G Q8}r
URL url = new URL(sURL); 2#/sIu-L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X(8LhsP
httpConnection.setRequestProperty("User-Agent","NetFox"); iO18FfM_
String sProperty = "bytes="+nStartPos+"-"; -r~9'aEs
httpConnection.setRequestProperty("RANGE",sProperty); <*/Z>Z_c2
Utility.log(sProperty); b=Ektq
@LS%uqs
J*6B~)Sp@
InputStream input = httpConnection.getInputStream(); XgeUS;qtta
//logResponseHead(httpConnection); 7xWJw
)"2eN3H/
,4-],~T
byte[] b = new byte[1024]; x'6i9]+r
int nRead; Q]RE,ZZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) DFRgn
{ id`RscV]
nStartPos += fileAccessI.write(b,0,nRead); WYcZD_
//if(nThreadID == 1) (hKjr1s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jzWgyI1b
} #~qzaETv,
fwUF5Y
$DnR[V}rR!
Utility.log("Thread " + nThreadID + " is over!"); WOeLn[
bDownOver = true; 1L?W+zMO
//nPos = fileAccessI.write (b,0,nRead); 8A-*MU`+
} 9.#")%_p
catch(Exception e){e.printStackTrace ();} J^PFhu
} R;&k/v
} hD,|CQ
D+q z`
[;:ocy
//打印回应的头信息 lKqFuLHwF
public void logResponseHead(HttpURLConnection con) iex]J@=e
{ x[+bLlb
for(int i=1;;i++) ,&* BhUC
{ YOvhMi
String header=con.getHeaderFieldKey(i); 2jkma :$'
if(header!=null) )}_}D+2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l>(*bb1}b
Utility.log(header+" : "+con.getHeaderField(header)); bhsCeH
else #~w~k+E4
break; g~9b_PY9
} $d.Dk4.ed
} >-w#&T &K
h^14/L=|
qc3,/JO1
public void splitterStop() @ @(O##(7
{ T5:xia>8O
bStop = true; 7pnlS*E.
} @2_E9{T
L(1} PZ
K]dR%j
} 45jImCm
:n%&
$_\x}`c~.
/* fZnq5rTk"
**FileAccess.java 0[7"Lhpd
*//文件访问(定位，写) XCXX(8To0=
package NetFox; "zqa:D26
import java.io.*; [l<&eI&ln
A2P.5EN
}"kF<gG1
public class FileAccessI implements Serializable{ dAM]ZR<
[ThAvQ_$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L EFLKC
RandomAccessFile oSavedFile; xv%]g=Q
long nPos; iYlkc
:<5jlpV(
6%wlz%Fp
public FileAccessI() throws IOException "t-9q
{ W!+=`[Ff
this("",0); ;Uy}(
} r-]%R:U*
)?6%d
={o)82LV
public FileAccessI(String sName,long nPos) throws IOException lB#7j
{ 5as5{"l
oSavedFile = new RandomAccessFile(sName,"rw"); q; C6ID`
this.nPos = nPos; OF-g7s6VH
oSavedFile.seek(nPos); slP>;
} HoeW6UV
J*Cf1 D5!
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public synchronized int write(byte[] b,int nStart,int nLen) IaO&f<^#o
{ ~K(mt0T)
int n = -1; BV}sN{
try{ EDF0q i
oSavedFile.write(b,nStart,nLen); .%M80X{5~
n = nLen; dqFp"Xe"%
} .CW,Td3f!
catch(IOException e) _E/
{ "2 :zWh7|
e.printStackTrace (); @V^5_K
} 2a 7"~z~
b+$wx~PLi
;r.#|b
return n; 0eK>QZ_
} oc[z dIk
{)Shc;Qh
um2}XI
} Wq}W )E
nmyDGuzk
>Y|P+Z\7
/* by,3A
**SiteInfoBean.java ~|LAe-e"
*/ Eb5BJ-XeS^
package NetFox; l=#b7rBP
/2tPd
J?hs\nA
public class SiteInfoBean { -q&,7'V
,F "P/`i'
Wo,93]
private String sSiteURL; //Site's URL 0;4 YU%u
private String sFilePath; //Saved File's Path TnQW~_:
private String sFileName; //Saved File's Name l701$>>
private int nSplitter; //Count of Splited Downloading File w")m]LV
? YluX
80Q%c(i
public SiteInfoBean() K=pG,[ChA
{//nSplitter的缺省值为5 '#Do( U'
//default value of nSplitter is 5 @,LU!#y(
this("","","",5); I\IDt~
} FiXqypT_(
F4ylD5Y!
x<.(fRv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^}J,;Zhu5
{ )d|s$l$?7
sSiteURL= sURL; #6pJw?[
sFilePath = sPath; ,)VAKrSg
sFileName = sName; h*3{IHAQ
this.nSplitter = nSpiltter; G+I->n-s4
!:}m-iqQ1
Deq@T {
} %:OX^^i;
nEbZ8M
TJZarNc$
public String getSSiteURL() Zt9ld=T
{ 8m[o*E.4F
return sSiteURL; ]]y,FQ,r
} Zvra >%
u EERNo&
bHXoZix
public void setSSiteURL(String value) ^SM5oK
{ {Eqx'j
sSiteURL = value; r-Y7wM`TZ
} u_FN'p=.
{]dvzoE]
"EE(O9q
public String getSFilePath() t oM+Bd:Y
{ [lu+"V,<LJ
return sFilePath; X}ihYM3y/
} U_Q;WPJ
uh>"TeOi
- Nt8'-
public void setSFilePath(String value) D<WGau2H
{ {CFy %
sFilePath = value; ]K%d
} 7`^=Ie%(K
KUUZN
0sCWIGUW
public String getSFileName() }j!C+i
{ /)?qD
return sFileName; ?D(aky#cyc
} 5'<a,,RKu
voJJoy%
7I;0%sVQ{
public void setSFileName(String value) O[p c$Pi
{ BA8!NR|
sFileName = value; =F5zU5`i
} Tr;&bX5]H
7;Vmbt9
'?LqVzZI
public int getNSplitter() -<e_^
{ IOJLJ p
return nSplitter; =?N$0F!
} 6}Rb-\N
}%^3
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public void setNSplitter(int nCount) ^g.HJQ'vF
{ [@]i_L[
nSplitter = nCount; Os!x<r|r
} 1@F>E;YjL=
} X?(R!=a
"I@akM$x
F;Q'R|HQ
/* u(PUbxJ V
**Utility.java xlh<}Vtp
*/ kjt(OFh'Y+
package NetFox; l%qh^0
by$mD_sr
~D`
public class Utility { U99Uny9
=c%gV]>G
#RKd>ig%
public Utility() _<l)4A3rS
{ LCe6](Z
57_AJT hR
Iv u'0vF
} Wq?vAnLbk
<oSx'_dc
//线程睡眠 Jyp7+M]
public static void sleep(int nSecond) p[;@9!t
{ 8~O0P=
try{ B3I0H6O
Thread.sleep(nSecond); >LB*5
} z$Qy<_l
catch(Exception e) \3hFb,/4k
{ tJm1Q#||
e.printStackTrace (); ;qcOcm%
} gf^y3F[\
} c(!pcB8
6QNZ/Ox:
//日志 _T;Kn'Gz(&
public static void log(String sMsg) Zm+GH^f'
{ 98vn"=3
System.err.println(sMsg); o)'06FF\$
} D4?cnwU
JM53sx4&
<L2z|%`
public static void log(int sMsg) H8m[:K]_H
{ R{6M(!x
System.err.println(sMsg); } V"A;5j`
} WE+Szg(4x
} /4upw`35]
c@KNyBy2
>GmO8dK
/* &4*f28 s
**TestMethod.java <y#@v G
*/ `9A`pC
package NetFox; J6@RIia
rmdg~
fVi[mH0=+
public class TestMethod { 48{B}j%oU
X9C:AGbp
y!|4]/G]?t
public TestMethod() +=*ND<$n/E
{ ///xx/weblogic60b2_win.exe //bQD>NBO
try{ Fw^^sB
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b27t-p8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Rhw+~gd*F
SiteFileFetch fileFetch = new SiteFileFetch(bean); 74hRG~
fileFetch.start(); 6t'.4SR
} -67!u;
catch(Exception e){e.printStackTrace ();} G}aM~,v
X<f4X"y
Ty*+?#`
} n} ]gAX
t$lJgj(
3(:?Z-iKe
public static void main(String[] args) g+xcKfN{
{ {J/+KK
new TestMethod(); 7'ws: #pC
} 7UUu1"|a|
} \vuWypo
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