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)); Zt[ PkBi
} +SUQRDF@i
for(int i=0;i<nEndPos.length-1;i++) u'Mq^8
{ AD*+?%hj
nEndPos = nStartPos[i+1]; M;\K+,
} > {fX;l
nEndPos[nEndPos.length-1] = nFileLength; n+Fl|4
} 3o"~_l$z
} %S$P+B?
MJ}VNv|S
9R'rFI
//启动子线程 89'nbg
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {{@3r5KGl
for(int i=0;i<nStartPos.length;i++) ;M@/AAZ
{ +c\fDVv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ec"L*l"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ``>WFLWTn
nStartPos,nEndPos,i); "b-6kM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a)y8MGx?
fileSplitterFetch.start(); N9,n/t
} sNS!/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;v8,r#4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); T][\wyLx1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k"GW3E;
nEndPos = " + nFileLength); B1*%pjy
// fileSplitterFetch[nPos.length-1].start(); lFI"U^xC
")x9A&p
sx*(JM}Be
//等待子线程结束 T'fE4}rY
//int count = 0; Jw;J$ u!d
//是否结束while循环 tao3Xr^?
boolean breakWhile = false; s&8QRI.
N:"E%:wSbi
G}}oeS
while(!bStop) Q:=s99
{ RFQa9Rxk
write_nPos(); LT2mwJl
Utility.sleep(500); ]2K>#sn-]
breakWhile = true; vV"TTzs!
2{@: :JZ
%DzS~5$G
for(int i=0;i<nStartPos.length;i++) -$[=AqJXp;
{ PJh\U1Z
if(!fileSplitterFetch.bDownOver) ?Mji'ZW}
{ F}i rCi47c
breakWhile = false; qX-Jpi P
break; tEBf2|<
} RQ}x7</{
} :jB(!XH
if(breakWhile) UmInAH4
break; p5G O@^i
<[l2]"Q
`I_%`15>
//count++; fs~n{z,ja%
//if(count>4) ]#S.L'
// siteStop(); a,lH6lDk
} '<6Gz7O
*"j_3vAx
H\^5>ccU>V
System.err.println("文件下载结束！"); wF3mQ_hv:@
} &<.Z4GxS
catch(Exception e){e.printStackTrace ();} q:1 1XPP
} 5\EHu8
?ix0n,m
Tff7SEP
//获得文件长度 >\(Ma3S
public long getFileSize() ~iF*+\
{ _lyP7$[: c
int nFileLength = -1; `C_#EU-
try{ @YWfq$23
URL url = new URL(siteInfoBean.getSSiteURL()); )k29mqa`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D1#E&4
httpConnection.setRequestProperty("User-Agent","NetFox"); sy/J+==
gjyg`%
$@8\9Y {
int responseCode=httpConnection.getResponseCode(); }[ux4cd8Y
if(responseCode>=400) +=u*!6S
{ ?uQ|?rk
processErrorCode(responseCode); bis/Nfr]
return -2; //-2 represent access is error ><`.(Z5c
} t6-c{ZX>A
%z8@;
[>Q{70 c[
String sHeader; ;hd> v&u#
ecf<(Vl}
!dVcnK1
for(int i=1;;i++) YF&SH)Y7
{ <uv{/L b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); T']*h8
//Utility.log(in.readLine()); >+,1@R
sHeader=httpConnection.getHeaderFieldKey(i); V~e1CZ(2X
if(sHeader!=null) <|Z0|sel
{ ;J?^M!l2=
if(sHeader.equals("Content-Length")) }1;Ie0l=_e
{ 4uU(t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); HT1bsY 0t
break; :GL|:
} n!HFHy2
} z{!wQ~ j
else fjp>FVv3
break; L=HL1Qe$G]
} a[9;Okm#
} m\@Q/_v
catch(IOException e){e.printStackTrace ();} 6LvUi|~"<
catch(Exception e){e.printStackTrace ();} E8NIH!dI
bIWcL$}4Q
:Q\h'$C
Utility.log(nFileLength); /hI#6k8o_
%R&3v%$y*
X4%*&L
return nFileLength; z$;%SYI
} ]]d@jj
a-%^!pN\M
k"Sw,"e>+
//保存下载信息（文件指针位置） !lu$WJ{M
private void write_nPos() #o yvsS8
{ rZpc"<U
try{ RJtSHiM2
output = new DataOutputStream(new FileOutputStream(tmpFile)); B8a!"AQ~5
output.writeInt(nStartPos.length); c1:op@t
for(int i=0;i<nStartPos.length;i++) L~ 1Lv?
{ |h6@hB\
// output.writeLong(nPos); }T(|\ X
output.writeLong(fileSplitterFetch.nStartPos); *?KQ\ Y
output.writeLong(fileSplitterFetch.nEndPos); |<BTK_R
} jv_sRV
output.close(); 1N#TL"lMS
} !uHI5k,f
catch(IOException e){e.printStackTrace ();} VQo7se1P
catch(Exception e){e.printStackTrace ();} 4] DmgOru%
} %o{vD&7\
wz6e^ g
MX9q )(:
//读取保存的下载信息（文件指针位置） wlKL|N
private void read_nPos() m+uh6IqN./
{ eJy@N
try{ )k7`!@ID
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KCCS7l/
int nCount = input.readInt(); rxDule3m
nStartPos = new long[nCount]; Ir}&|"~H
nEndPos = new long[nCount]; =20Q!wcu
for(int i=0;i<nStartPos.length;i++) Tmw :w~
{ S2fw"1h*x
nStartPos = input.readLong(); ;#Mq=Fr-SG
nEndPos = input.readLong(); {[Yv@CpN
} yyA/x,
input.close(); 93'%aSDI%
} ,;D74h2F
catch(IOException e){e.printStackTrace ();} Y%&6qt G
catch(Exception e){e.printStackTrace ();} =,0E3:X^
} N!Y'W)i16
:fj}J)9'xW
]j{S' cz
private void processErrorCode(int nErrorCode) nh E!Pk
{ ec]ksw6T+
System.err.println("Error Code : " + nErrorCode); ~Q]B}qdm
} %[p[F~Z^Z
8D+OF 6CM
mIr{Wocx
//停止文件下载 +Oyt
public void siteStop() Dt+"E
{ !HB,{+25
bStop = true; r/{VL3}F_e
for(int i=0;i<nStartPos.length;i++) Jk1Up2#B
fileSplitterFetch.splitterStop(); (p2\H>pTr
x]{h$yI
O~t5qnu/}
} ]1Q\wsB
} n1cAI|ZE
//负责部分文件的抓取 vb70~k
**FileSplitterFetch.java ,,G0}N@7s
*/ HV?awc
package NetFox; AN.`tv
JdV!m`XpXy
u_Q3v9
import java.io.*; zBoU;d%p>
import java.net.*; 1-qQp.Wj
4wBCs0NIm
5w1=j\oq
public class FileSplitterFetch extends Thread { aFC3yMKXh
+HfjnEbtBs
IC{>q3
String sURL; //File URL [&zP$i&
long nStartPos; //File Snippet Start Position E?FPxs
long nEndPos; //File Snippet End Position wZOO#&X#r
int nThreadID; //Thread's ID Q% dpGI
boolean bDownOver = false; //Downing is over d-?~O~qD|!
boolean bStop = false; //Stop identical Mv9s
FileAccessI fileAccessI = null; //File Access interface iYnw?4Y
c~tkY!c
DvhK0L*Qr
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @E==~ b
{ TIvLY5 HG
this.sURL = sURL; 7C 4Njei"
this.nStartPos = nStart; $[>wJXj3R
this.nEndPos = nEnd; >"Hj=?
nThreadID = id; F^aD!O ~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cw^FOV*
} 8F@6^9C
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W&*{j;e9%I
public void run() :]//{HF
{ ioviJ7N% O
while(nStartPos < nEndPos && !bStop) b;}MA7=
{ ct]5\g?U'
F_-yT[i
Al` ;SWN
try{ A] F K\
URL url = new URL(sURL); W5x]bl#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v |i(peA#
httpConnection.setRequestProperty("User-Agent","NetFox"); 5fLCmLM`
String sProperty = "bytes="+nStartPos+"-"; YJ"gm]Pm
httpConnection.setRequestProperty("RANGE",sProperty); \u)(+t{
Utility.log(sProperty); }5]NUxQ_
2+^#<Uok
grS,PKH
InputStream input = httpConnection.getInputStream(); *r%
//logResponseHead(httpConnection); 2?"9NQvz
T[7DJNdG6
6iTDk
byte[] b = new byte[1024]; *U]f6Q<X
int nRead; SEuj=Vie#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dE^'URBiA
{ y=&)sq
nStartPos += fileAccessI.write(b,0,nRead); u.arkp
//if(nThreadID == 1) hrW.TwK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #uH1!UQb
} hyBSS,I
OI-%Ig%C#l
T0SD|'
Utility.log("Thread " + nThreadID + " is over!"); NH?s
bDownOver = true; XkNi'GJf
//nPos = fileAccessI.write (b,0,nRead); c]n4vhUa5
} `Yut1N
catch(Exception e){e.printStackTrace ();} J7$=f~$
} ;m&f Vp
} i|=XW6J%
*$s)p>
1'd "O @
//打印回应的头信息 [OT@gp:
public void logResponseHead(HttpURLConnection con) F6 UOo.L)I
{ INkrG.=u
for(int i=1;;i++) MBg^U<t8
{ YnNei 7R
String header=con.getHeaderFieldKey(i); s_kI\w4(x1
if(header!=null) 9sRP8Nj|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OrH&dY
Utility.log(header+" : "+con.getHeaderField(header)); crmnh4-
else ~svu0[Vx
break; Pq`4Y K
} ;ndg,05_
} k"n#4o:
{1qEN_ERx
bLUn0)c
public void splitterStop() AUN Tc3
{ R `'@$"
bStop = true; W]R5\G*
} G3e%~
P]y5E9 k
IMrB!bor
} EdU3k'z$
X~R qv5@-
`|v#x@s
/* @emZwN"m
**FileAccess.java [0rG"$(0Y
*//文件访问(定位，写) )WzCUYE1/
package NetFox; Dp'/uCW)
import java.io.*; ?Jma^ S
>:K3y$]_
Oc8+an1m
public class FileAccessI implements Serializable{ lmd0Q(I
}^iE|YKz
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Nd0Wt4=
RandomAccessFile oSavedFile; 8(+X0}
long nPos; n^A=ar.
2ru6bIb;
Vs"M Cqi
public FileAccessI() throws IOException <^&'r5H
{ Obd!
this("",0); N7e^XUG
} =GpLlJ`-
ar{e<&Bny
Ylf6-FbF
public FileAccessI(String sName,long nPos) throws IOException K}zw%!ex
{ Lf,gS*Tg?
oSavedFile = new RandomAccessFile(sName,"rw"); l%)XPb2$J
this.nPos = nPos; G'bp
oSavedFile.seek(nPos); [;b9'7j'
} l==T3u r
1HZexV
qzG'Gz{{qu
public synchronized int write(byte[] b,int nStart,int nLen) %GIla*
{ ]f\rB8k|&
int n = -1; ="4jk=on
try{ ;P{ *'@
oSavedFile.write(b,nStart,nLen); OO@$jXZB
n = nLen; i44`$ps
} :4A^~+J
catch(IOException e) d EXw=u
{ (2{1m#o
e.printStackTrace (); 6m{3GKaW~
} X$xqu\t7
}skXh_Vu4
HS2)vd@)
return n; M5q7` }>G
} M"J$c42
t EN%mK
rUuM__;d
} 1]qhQd-u
-@QLE}~k[
OU[Sm7B
/* `,|7X]%b
**SiteInfoBean.java 5H5<ft,
*/ dW=]|t&
package NetFox; I7}[%(~Sf/
&2g1Oy~
D]0#A|nF
public class SiteInfoBean { 7_|zMk.J*
1,/oS&?E
)i?wBxq'MA
private String sSiteURL; //Site's URL TcqqAc
private String sFilePath; //Saved File's Path ?iq:Gf
private String sFileName; //Saved File's Name h;Bol
private int nSplitter; //Count of Splited Downloading File :xA'X+d/'
SAqX[c
6dNo!$C^
public SiteInfoBean() ;+5eE`]a/L
{//nSplitter的缺省值为5 7[K$os5al
//default value of nSplitter is 5 %8v?dB;>x`
this("","","",5); ,,6e }o6
} /1^%32c
[k.<x'#
v3[ 2!UXq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7N:,F9V<
{ #-{4 Jx
sSiteURL= sURL; 5bAy@n
sFilePath = sPath; !W6]+
sFileName = sName; [#.QDe
this.nSplitter = nSpiltter; .NPai4V'
m*(8I=]q
ed617J
} ]v+\v re
-Z#A}h
wWH5T}\
public String getSSiteURL() \_+d*hHF~
{ Bp b_y;E
return sSiteURL; sqkPC_;A
} K/08F|]a
Xf.SJ8G
Z*oGVr g
public void setSSiteURL(String value) PB`94W
{ z,^baU
sSiteURL = value; ,H|V\\
} Iz ,C!c
\oaO7w,:"
:lcoSJ
public String getSFilePath() "eBpSV>nnQ
{ Y(-+>>j_
return sFilePath; >`t |a
} [aIQ/&Y
05w_/l+
p^^<BjkQ
public void setSFilePath(String value) R@ihN?k
{ mH;\z;lyK
sFilePath = value; @Gl=1
} TT>;!nb
j{nL33T%
)WD<Q x&
public String getSFileName() &OsJnkY<<
{ g<tr |n
return sFileName; Y>IEB,w
} f BukrPsV
>+&524xc
eAPGy-
public void setSFileName(String value) 1_f(;WOg
{ %[5hTf
sFileName = value; qWy(f|:hYi
} (Y:5u}*Y
cbNrto9
6 fL=2a
public int getNSplitter() )%gigQZ+
{ /u5MAl.<[
return nSplitter; C#+Gkzq
} 6"z:s-V
Q.@9"&)t
YG$Y4h" @"
public void setNSplitter(int nCount) jq%Qc9y
{ #T&''a
nSplitter = nCount; 0)+F}SyyD
} '4ftclzL
} j$,:cN
Qv|A^%Ub!
7$Jb"s
/* +CaPF
**Utility.java 3Oy?_a$
*/ ]*D=^kA0[
package NetFox; COZ<^*=A#p
;&oS=6$
P|l62!m<
public class Utility { I^emH+!MW
I& DEF*
"sdzm%
public Utility() Ho2#'lSKM
{ &Y4S[-
%`?IY<
jEo)#j];`<
} 59 R;n.Q
!#Ub*qY1Z
//线程睡眠 i]Njn k
public static void sleep(int nSecond) scT,yNV
{ $qV, z
try{ & =)HPzC
Thread.sleep(nSecond); \QGh@AQp"
} Op0n.\>
catch(Exception e) p(=}Qqdr8
{ Cjc>0)f&.
e.printStackTrace (); +`}QIp0
} ibAZ=RD
} *eK\W00
"wy|gnQJ
//日志 MAb*4e#
public static void log(String sMsg) x-1RmL_%
{ qr~P$
System.err.println(sMsg); Jz<-B
} 98'/yZ
g0O~5.f
1DLAfsLlj
public static void log(int sMsg) 6V-u<FJ
{ *t=8^q(K[
System.err.println(sMsg); mE\sD<b
} D<U^FT
} M#Kke9%2
Y7vUdCj
l1HMH?0|
/* jlXzfDT
**TestMethod.java 'guXdX]Gu
*/ 3CcCcZ9I
package NetFox; X$BN&DD
fqpbsM;M]
2@~.FBby7@
public class TestMethod { !LJEo>D
ua%@Ay1|
,Pi!%an w
public TestMethod() [ICFPY6
{ ///xx/weblogic60b2_win.exe S#Q0aGj
try{ JJe8x4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !:Z lVIA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8z1#Q#5
SiteFileFetch fileFetch = new SiteFileFetch(bean); WVZ](D8Gc]
fileFetch.start(); [`J91=
} lDsT?yHS`Z
catch(Exception e){e.printStackTrace ();} nQ*9E|Vx
+{#65z
OEiu,Y|@l
} >f$NG
#K#BNpG|
/|s~X@%K
public static void main(String[] args) 27J!oin$
{ Cfs2tN
new TestMethod(); vG'6?%38
} 3-~*
} _nwsIjsW
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