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)); RhvfC5Hq
} "B8"_D&
for(int i=0;i<nEndPos.length-1;i++) JGH60|
{ HjGyj/78w
nEndPos = nStartPos[i+1]; ]f_6 '|5A
} 9>g,
nEndPos[nEndPos.length-1] = nFileLength; 'I /aboDB
} stk9Ah
} y;AL'vm9
K%X^n>O7C
D*YM[sN`
//启动子线程 aN $}?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YI.w-K\
for(int i=0;i<nStartPos.length;i++) i7utKj*57
{ d R]Q$CJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o`q_wdy?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), YcN!T"wJ@
nStartPos,nEndPos,i); <1.A=_ M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ulER1\W
fileSplitterFetch.start(); "eWYv3z~-
} &_gTD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _!?Hu/zo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rJ!{/3e
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", NM6Teu_
nEndPos = " + nFileLength); P b]3&!a
// fileSplitterFetch[nPos.length-1].start(); e4z1`YLsG
+5&wOgx
-M1YE
//等待子线程结束 P7x =
//int count = 0; H_ez'yy
//是否结束while循环 ,+ #6Y_
boolean breakWhile = false; }A:<%N
0`I-2M4F*Q
Iy.rqc/86
while(!bStop) -pE(_
{ {vN}<f`
write_nPos(); YNBHBK4;
Utility.sleep(500); ,s_T pq
breakWhile = true; EgDQ+( -
H=\!2XS
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for(int i=0;i<nStartPos.length;i++) W{rt8^1
{ &%_& 8DkG
if(!fileSplitterFetch.bDownOver) .]9c/
{ T1r3=Y4
breakWhile = false; WMBm6?54
break; `r_m+]
} ( &frUQm
} =Mb1o[
if(breakWhile) (}5S
break; s9>(Jzcf9
2*w:tT8+X
~(@ E`s&{
//count++; q9^
//if(count>4) X2xuwA
// siteStop(); R3!@?mcr
} Y&^P"Dw
1 `7<2w
Vm|Y$C
System.err.println("文件下载结束！"); {" 4e+y
} ad_`x
catch(Exception e){e.printStackTrace ();} \6 93kQ
} ee/&/Gt
#%FN>v3e
3w!c`;c%
//获得文件长度 }=2;
public long getFileSize() 7rC uu*M
{ pMJ1v
int nFileLength = -1; .y&QqxiE
try{ rJo"fx
URL url = new URL(siteInfoBean.getSSiteURL()); /2m?15c+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LsM7hLy
httpConnection.setRequestProperty("User-Agent","NetFox"); 6y5A"-
5&f{1M6l>
+~ #U7xgq/
int responseCode=httpConnection.getResponseCode(); tWdhDt8$&
if(responseCode>=400) Fbp{,V@F2
{ w?,M}=vg
processErrorCode(responseCode); Y=T'WNaL)0
return -2; //-2 represent access is error ZK'-U,Y.H7
} c0Dmq)HK?
kpI{KISQu
P N*JR
String sHeader; olW|$?
q,2]5'
.Xdj(_&
for(int i=1;;i++) _7D_72
{ i0s6aAhgJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2nFy`|aA%
//Utility.log(in.readLine()); 3<?XTv-
sHeader=httpConnection.getHeaderFieldKey(i); G8IY#
if(sHeader!=null) T'fcc6D5p
{ oQ7]=|
if(sHeader.equals("Content-Length")) 0gn@h/F2%
{ /V?H4z[G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }N*>QR5K
break; L@^~N$G&u
} w~@-9<^K]v
} (.Lrmf@hI7
else {R^'=(YFy
break; sgr=w+",Q
} Sc]P<F7N]
} 2Nj9U#A
catch(IOException e){e.printStackTrace ();} 8:.nEo'
catch(Exception e){e.printStackTrace ();} e2C<PGUUB
Ft@Wyo`^
#2tCV't
Utility.log(nFileLength); ZE`lr+_Y
XTDE53Js&
60Z]M+8y8
return nFileLength; w&BGJYI
} ntP|\E
b59{)u4F
3qQUpm+
//保存下载信息（文件指针位置） {$M;H+Foh
private void write_nPos() ?_`0G/xl
{ 111D3
try{ $A}QY5`+~S
output = new DataOutputStream(new FileOutputStream(tmpFile)); M"_FrIO
output.writeInt(nStartPos.length); jFerYv&K~
for(int i=0;i<nStartPos.length;i++) )nu~9km3
{ <TNk?df7
// output.writeLong(nPos); LihjGkj\g
output.writeLong(fileSplitterFetch.nStartPos); (H?ZSeWx
output.writeLong(fileSplitterFetch.nEndPos); Z7jX9e"L
} gNx+>h`AF
output.close(); uvA(Rn
} _B,_4}
catch(IOException e){e.printStackTrace ();} 9B)(>~q
catch(Exception e){e.printStackTrace ();} @gSkROCdC)
} Bfd-:`Jk
X;!D};;M
xiyxrR;
//读取保存的下载信息（文件指针位置） +[m8c){
private void read_nPos() iQ^: ])m>
{ <3hA!$o~
try{ K<v:-TjQZ:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %q_Miu@
int nCount = input.readInt(); 9YF$CXonE=
nStartPos = new long[nCount]; Gowp <9 F
nEndPos = new long[nCount]; MjaUdfx
for(int i=0;i<nStartPos.length;i++) D*vm cSf
{ |)W!jC&k
nStartPos = input.readLong(); Ak~4|w-
nEndPos = input.readLong(); ;TZGC).6
} `dJDucD
input.close(); ["3df>!f
} Poa?Ej
catch(IOException e){e.printStackTrace ();} =z:U~D
catch(Exception e){e.printStackTrace ();} P ,K\
} NE"jh_m-
AH.9A_dG
xfSG~csoz
private void processErrorCode(int nErrorCode) *rqm8z50a
{ R#4^s
System.err.println("Error Code : " + nErrorCode); 2r];V'r
} zL s^,x
!;>(ie\
{aN(d3c
//停止文件下载 Fu8 7fVi/\
public void siteStop() }gsO&g"8
{ C4$/?,K(
bStop = true; ]2+g&ox4'
for(int i=0;i<nStartPos.length;i++) hbuZaxo<
fileSplitterFetch.splitterStop(); r3I,11B
4Y tk!oS`
!W1eUY
} GH'O!}
} JZ`L%
//负责部分文件的抓取 N_C_O$j
**FileSplitterFetch.java xKp0r1}
*/ |0{ i9.=
package NetFox; n_$yV:MuT!
6CNS%\A
0^]t"z5f0
import java.io.*; w1B<0'#
import java.net.*; ^i<}]c_|f
;mO,3dV
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public class FileSplitterFetch extends Thread { p27p~b&
|*Ot/TvG
\Tq"mw9P
String sURL; //File URL kqB\xlS7k
long nStartPos; //File Snippet Start Position "@/ba!L+
long nEndPos; //File Snippet End Position ]Sta]}VQ
int nThreadID; //Thread's ID Bt>}LLBS2
boolean bDownOver = false; //Downing is over DY><qk
boolean bStop = false; //Stop identical &]nd!N
FileAccessI fileAccessI = null; //File Access interface oA3d^%(c
|}qjqtZ
a@|.;#FF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1<uwU(
{ tE!'dpG5)
this.sURL = sURL; Mn"/#tXL-
this.nStartPos = nStart; Riql,g/
this.nEndPos = nEnd; h3J*1
nThreadID = id; |vy]8?Ak
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Tkrx7Cs(
} !C7<sZ`C
-,>:DUN2
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public void run() \ j]~>9
{ $T*KaX\{B
while(nStartPos < nEndPos && !bStop) E:Y:X~vy
{ LrM}?9'
onzA7Gre
q[boWW
try{ ZA.fa0n
URL url = new URL(sURL); ",ad7Y7i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yQS04Bl]
httpConnection.setRequestProperty("User-Agent","NetFox"); }'jV/
String sProperty = "bytes="+nStartPos+"-"; Kcn\g.
httpConnection.setRequestProperty("RANGE",sProperty); EW5]!%
Utility.log(sProperty); v,\93mNp[
SY6r 8RK
J%4HNW*p
InputStream input = httpConnection.getInputStream(); K%<GU1]-]
//logResponseHead(httpConnection); d2ofxfpg+
/:6Q.onmLn
tG 7+7Z=
byte[] b = new byte[1024]; zZYHc?Z
int nRead; |B1Af
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !?r/ 4
{ 3ExVZu$
nStartPos += fileAccessI.write(b,0,nRead); /$OIlu
//if(nThreadID == 1) ^4hc+sh0D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,'-?:`hP'
} ,%='>A
aa=b<Cd
!@yQK<0
Utility.log("Thread " + nThreadID + " is over!"); 4H7Oh*P\j
bDownOver = true; gCwt0)
//nPos = fileAccessI.write (b,0,nRead); LO>8 j:
} !>|`ly$6
catch(Exception e){e.printStackTrace ();} cX"G7Bh
} 3qcpf:
} q+J0}y{#8)
_U=S]2QW
'X ~Ab
//打印回应的头信息 2e\Kw+(>{
public void logResponseHead(HttpURLConnection con) f}-v
{ "sIN86pCs
for(int i=1;;i++) ypT9 8
{ &O{t^D)F
String header=con.getHeaderFieldKey(i); jhcuK:`L
if(header!=null) h~.V[o7=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #[(0tc/
Utility.log(header+" : "+con.getHeaderField(header)); #J3zTG(:@
else Ris-tdg
break; c.6QhE
} ,|QU] E @
} Pd&,G$l
/]l f>\x1
s|p(KWo2U
public void splitterStop() Wlxk
{ 5YLho2h38!
bStop = true; xx}'l:}2]
} 'T{pdEn8u
Q}ZBr^*]1e
tJG (*
} k#-[ M.i
p|;o5j{
SOYDp;j
/* ep`/:iYW
**FileAccess.java @s?oJpo
*//文件访问(定位，写) {!tOI
package NetFox; zlN+edgY#,
import java.io.*; fX$6;Ae
b`?M9f5
t3M0La&
public class FileAccessI implements Serializable{ KD9Ca $-
B4 <_"0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OT"lP(,
RandomAccessFile oSavedFile; ]:Wb1
long nPos; R=QM;
H;X~<WN&AW
G)K9la<p
public FileAccessI() throws IOException !zl/0o
{ "9.6\Y\*
this("",0); ~v,!n/('
} hXBqz9
@)06\h
Q,O]x#
public FileAccessI(String sName,long nPos) throws IOException <6gU2@1
{ M`q#,Y?3^I
oSavedFile = new RandomAccessFile(sName,"rw"); J~:kuf21
this.nPos = nPos; 2%*|fF}I
oSavedFile.seek(nPos); :nTkg[49pJ
} )8\Z=uC
Vc{/o=1u
MEDskvBG
public synchronized int write(byte[] b,int nStart,int nLen) /}[zA@
{ p$&_fzb
int n = -1; oF`-cyj"
try{ 8APTk
oSavedFile.write(b,nStart,nLen); Q&tFv;1w6
n = nLen; baA HP"
} mn,=V[f
catch(IOException e) #`2GAM];7
{ 7Ljs4>%l9j
e.printStackTrace (); chMt5L+5
} 69[w/\
`z5v}T
#=>kw^5
return n; ye9QTK6$,
} A/r;;S)%2
F&-5&'6G+
%_cg|yy
} CA'hvXb.
ZD iW72&Q
%pQdq[J={
/* V:$[~)k8
**SiteInfoBean.java AJdlqbd'+
*/ ^S>!kt7io
package NetFox; eo-XqiJ,]
u_$6LEp-
zkw0jX~
public class SiteInfoBean { tVK?VNW
!hpTyO+%
c|8KT
private String sSiteURL; //Site's URL P1vF{e
private String sFilePath; //Saved File's Path k B$lkl\C
private String sFileName; //Saved File's Name WllCcD1
private int nSplitter; //Count of Splited Downloading File Zm?G'06
.f[\G*
h?M'7Lti
public SiteInfoBean() :z}~U3,JE
{//nSplitter的缺省值为5 K.c6Rg
//default value of nSplitter is 5 Fvcq^uZ
this("","","",5); o%QhV6(F
} ,5%aP%
V1AEjh
4{1c7g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) GZ-n! ^
{ aa'0EU:
sSiteURL= sURL; (*c`<|)
sFilePath = sPath; -#:Y+"'
sFileName = sName; !^Qb[ev
this.nSplitter = nSpiltter; u:p:*u_^I
+Uc&%Px
\ltErd-
} D z]}@Z*jK
C[HE4xF6
VbY>l' rY
public String getSSiteURL() (W{rv6cq
{ j8F~j?%!
return sSiteURL; u/K)y:ZZ
} BBZ)H6TzL
:$u{
F\YcSDM
public void setSSiteURL(String value) cPa 0n4
{ ACMpm~C8Gu
sSiteURL = value; 8O}A/*1FJ
} &)/H?S;yN
j/; @P
pU\xzLD
public String getSFilePath() '8((;N|I^
{ }*{\)7g
return sFilePath; UeC%Wa<[
} P+D|_3j
#z1ch,*3;
jn#N7%{Mk
public void setSFilePath(String value) G> 5=`
{ )PanJHtU
sFilePath = value; 8EVF<@{]
} }(hYG"5
6H. L!tUI
Jh/M}%@|
public String getSFileName() Dq_{O
{ 4jue_jsle
return sFileName; e`gGzyM
} Q?I"J$]&L
ADJ5ZD<Q
dk, I?c&
public void setSFileName(String value) UO7a}Tz<
{ Iu)(Huv
sFileName = value; =QO1FO
} 2*UE&Gp
9-e[S3ziM
(J?}eb;>n
public int getNSplitter() IQIb\OUo!v
{ xaq=?3QOH
return nSplitter; .w*{=x0k
} JJZXSBAOU
9lazo
=6q*w^ET
public void setNSplitter(int nCount) >8{`q!=|~
{ XiZ Zo
nSplitter = nCount; `'tw5}
} D;#Yn M3
} ]$`s}BN
{D_4~heF
* y"GgI
/* Ar{=gENn
**Utility.java vNwSZ{JBd
*/ ;@ !d!&
package NetFox; /VjbyRwV
)Q pP1[
:Y)kKq d
public class Utility { e7j]BzGvl
L)//- k9
+#*z"a`
public Utility() :J)lC =
{ ,Elga}7u
DF&jZ[##
dXcMysRc%&
} 3B_} :
4Hd@U&E
//线程睡眠 2|_Jup
public static void sleep(int nSecond) T`2fPxM:cZ
{ PXQ9P<m
try{ uB)6\fkTB
Thread.sleep(nSecond); <raqp Oo&
} y<LwrrJ>
catch(Exception e) bz,cfc;?$
{ }_D5, k
e.printStackTrace (); Iy 8E$B;
} )PZ}^Fa
} 3U.B[7fOM
jKi*3-&
//日志 T4, Zc
public static void log(String sMsg) ,IvnNnl2
{ B7jlJqV
System.err.println(sMsg); oG_'<5Bv>
} $@f3=NJ4k
rp[oH=&
UDi3dH=
public static void log(int sMsg) rM?Dp2
{ m$UT4,Ol
System.err.println(sMsg); Q Fqv,B\<
} })u}PQ
} es(LE/`e
";Xbr;N
0FR%<u
/* ).`a-Pv
**TestMethod.java t 6IaRD
*/ zinl.8Uk
package NetFox; *9:6t6x
tMk>Bx9[
gkn/E}K#
public class TestMethod { bb_jD^
OcS`Fxs
6V?&hq&t
public TestMethod() |JQP7z6j]
{ ///xx/weblogic60b2_win.exe hADb]O
try{ w`!foPE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w 4gZ:fR=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5J#gJFA
SiteFileFetch fileFetch = new SiteFileFetch(bean); nv[Sb%/
fileFetch.start(); ,* vnt6C*
} s3RyLT
catch(Exception e){e.printStackTrace ();} '\mZ7.Jj
3#ZKuGg=
{3uSg)
} Wjk;"_"gd
!P^$g R
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public static void main(String[] args) oK1[_ko|
{ i|noYo_Ah\
new TestMethod(); 9i[2z:4HJ
} /lok3J:
} Gqc6).tn
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