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)); b}< T<
} ma[%,u`
for(int i=0;i<nEndPos.length-1;i++) c[J(H,mt/
{ A(G%9'T
nEndPos = nStartPos[i+1]; v=e`e68U~
} kIhP 73M
nEndPos[nEndPos.length-1] = nFileLength; $#4Qv5}
} EjW3_ %
} VI7f}
$mOVo'2
nXPl\|pXt
//启动子线程 '8\7(0$c
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Uyf<:8U\
for(int i=0;i<nStartPos.length;i++) P,U$ X+
{ yW5/Y02
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C4wJSQl_I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2u9O+]EP
nStartPos,nEndPos,i); G<n(\85X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )@+lfIE(l
fileSplitterFetch.start(); $BHbnsaQ
} ]5| o8.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "zFv?ay
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u"eO&Vc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =OY&;d!C
nEndPos = " + nFileLength); X,-QxV=lc)
// fileSplitterFetch[nPos.length-1].start(); ZI.;7G@|
I3sH8/*
x?s5vxAKf
//等待子线程结束 CR8a)X4j#
//int count = 0; n.9k<
//是否结束while循环 ]gHxvT\E
boolean breakWhile = false; M]9oSi
GjTj..G/
/IQl
while(!bStop) mBWE^
{ ,K4*0!TXP
write_nPos(); '2)c;/-E
Utility.sleep(500); 1K(a=o[Ce
breakWhile = true; ~{69&T}9
P(iZGOKUs=
Ce&nMgd~
for(int i=0;i<nStartPos.length;i++) 0u0<)gdX
{ %1f, 8BM
if(!fileSplitterFetch.bDownOver) ?naPti1GX
{ QG{).|pm
breakWhile = false; n =SY66
break; <eWGvIEP[
} 6AS'MD%&
} 8R!3}kx
if(breakWhile) @q=l H *=
break; %cIF()
7\.Ax
00DWXGt20o
//count++; ,$;g'z!N
//if(count>4) t<`h(RczHI
// siteStop(); %y@iA91K
} /D9FjOP
iQ[0d.(A
eFO+@
System.err.println("文件下载结束！"); F[aow$",+}
} iz|mJUx
catch(Exception e){e.printStackTrace ();} re.%$D@
} ~&E|;\G
>v4k_JX
|=OO$z;q|
//获得文件长度 9&'I?D&8
public long getFileSize() [\9WqHs
{ vBUl6EmWu
int nFileLength = -1; A<6V$e$:2
try{ )9,*s!)9
URL url = new URL(siteInfoBean.getSSiteURL()); eYL7G-3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ru%: z>Y
httpConnection.setRequestProperty("User-Agent","NetFox"); `[+9n2j
7f4R5c
d6lhA7
int responseCode=httpConnection.getResponseCode(); !'14mN#A
if(responseCode>=400) r#{r]q_E*
{ &77]h%B>
processErrorCode(responseCode); v}6YbY Tq
return -2; //-2 represent access is error uo1G
} _/[n/"gn
1fbd/-h
Rl4r9
String sHeader; i'!M<>7
;F&wGe
$,k SR}
for(int i=1;;i++) ?o0#h
{ hp(n;(OR
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ` n{rzenPX
//Utility.log(in.readLine()); A>L(#lz#ek
sHeader=httpConnection.getHeaderFieldKey(i); @C=, >+D
if(sHeader!=null) $"{V],:T |
{ 4Uz:zB
if(sHeader.equals("Content-Length")) f}4c#x
{ ^F*)Jq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *f8,R"]-g
break; @];#4O
} Fga9
} NrvS/cI!t
else ~QdwoeaD
break; Pi?*rr5WZ
} +!POKr
} 9\)NFZ3Mz
catch(IOException e){e.printStackTrace ();} kyJv,!};
catch(Exception e){e.printStackTrace ();} n#3y2,Ml
We#*.nr{3Z
#py7emu
Utility.log(nFileLength); p!'wOThO`
_|8"&*T^
_0F6mg n
return nFileLength; }sy3Mrb
} va8:QHdU
1,PFz
tBBN62^X
//保存下载信息（文件指针位置） NtTLvO6
private void write_nPos() Op3 IL/
{ v,>F0ofJ
try{ %o4d43uZ
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2|}p&~G(
output.writeInt(nStartPos.length); Wr)%C
for(int i=0;i<nStartPos.length;i++) >\DXA)nc
{ ]^ O<WD
// output.writeLong(nPos); N83RsL "}_
output.writeLong(fileSplitterFetch.nStartPos); lYw A5|+
output.writeLong(fileSplitterFetch.nEndPos); 6%S>~L66
} }Tc)M_
output.close(); /LSiDys
} |P?8<8p
catch(IOException e){e.printStackTrace ();} ,A6*EJ\w
catch(Exception e){e.printStackTrace ();} r~s03g0
} n;rOH[P
0jq&i#yNB
l3g6y9;
//读取保存的下载信息（文件指针位置） hChM hc
private void read_nPos() %oor7 -l
{ r LfS9H
try{ *fd` .}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %Vt@7SwRJ
int nCount = input.readInt(); /asyj="N7
nStartPos = new long[nCount]; Gj)Qw6
nEndPos = new long[nCount]; }p- %~Y
for(int i=0;i<nStartPos.length;i++) v>R.M"f
{ rz7yAm
nStartPos = input.readLong(); PPq*_Cf
nEndPos = input.readLong(); ))KsQJ"V
} 2!6Kzq
input.close(); O3BU.X1'%
} 1$Hf`h2
catch(IOException e){e.printStackTrace ();} v<c Hx/
catch(Exception e){e.printStackTrace ();} lmc-ofEv
} }E1Eq
\U-5&,fP
1b!l+ 8!
private void processErrorCode(int nErrorCode) 11-uJVO~*
{ $OhL 95}7
System.err.println("Error Code : " + nErrorCode); 9=}/t9k
} B+Bv(p
5g5pzww
k m|wB4
//停止文件下载 kt:%]ZZL
public void siteStop() T a[74;VO
{ !*ucVv;
bStop = true; uA,{C%?
for(int i=0;i<nStartPos.length;i++) Uh8ieb
fileSplitterFetch.splitterStop(); a$|u!_)!h
a|53E<5X
2M1mdkP3
} YOoP]0'L
} $.cGRz
//负责部分文件的抓取 1lQ10J
**FileSplitterFetch.java W P&zF$
*/ t8+93,*B
package NetFox; _t[%@G>P
$3Ia+O
'ng/A4
import java.io.*; !{XO#e
import java.net.*; y$"L`*W
OE"Bb
gA|j\T{c
public class FileSplitterFetch extends Thread { ?C{N0?[P-
<>oW f
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String sURL; //File URL ;v'Y'!-J
long nStartPos; //File Snippet Start Position <coCu0
long nEndPos; //File Snippet End Position el%Qxak`"
int nThreadID; //Thread's ID y_&XF>k91
boolean bDownOver = false; //Downing is over 7EXmmB~>,
boolean bStop = false; //Stop identical $gTPW,~s[
FileAccessI fileAccessI = null; //File Access interface eH8.O
yB1>83!q
AVWrD[ wD2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3"n8B6
{ A&'%ou
this.sURL = sURL; SAJ=)h~
this.nStartPos = nStart; :JIPF=]fc
this.nEndPos = nEnd; ( -@>
nThreadID = id; 1aG}-:$t'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 aB)DX
} v],DBw9
nE;gM1I
1%`:8
public void run() 0Kk*~gR?
{ MvmP["%J4_
while(nStartPos < nEndPos && !bStop) oUSG`g^P(M
{ S/;Y4o
m5X=P5U
7p$*/5fk
try{ tV9C33
URL url = new URL(sURL); )M 0O=Cl1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^nF$<#a
httpConnection.setRequestProperty("User-Agent","NetFox"); `qz5rPyZ
String sProperty = "bytes="+nStartPos+"-"; :nUsC+oBS
httpConnection.setRequestProperty("RANGE",sProperty); 9A(K_d-!H
Utility.log(sProperty); dCTpO
>}*jsqaVU
M3 u8NRd5|
InputStream input = httpConnection.getInputStream(); E5{)d~q
//logResponseHead(httpConnection); @&##c6\$
A5ID I<a
hp4(f W
byte[] b = new byte[1024]; P;LZ!I
int nRead; nn:pf1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;@ X
{ vh8Kd' y
nStartPos += fileAccessI.write(b,0,nRead); q"<-
//if(nThreadID == 1) !\O,dq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b.*4RL
} ~HRWKPb
'LLx$y.Ei[
3uG5b8?
Utility.log("Thread " + nThreadID + " is over!"); 2(//slP
bDownOver = true; "]Dzc[Vp
//nPos = fileAccessI.write (b,0,nRead); .@-]A
} [F[<2{FQF
catch(Exception e){e.printStackTrace ();} k.[) R@0%
} NOp=/
} 4(GgaQFO?
@zF:{=+]+
g*r;( H>e
//打印回应的头信息 =w$"wzc
public void logResponseHead(HttpURLConnection con) -L?% o_
{ m+{: ^
for(int i=1;;i++) }QW~.>`
{ bk9~63tN+>
String header=con.getHeaderFieldKey(i); -0WCwv
if(header!=null) T8TsKjqOZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^GaPpm
Utility.log(header+" : "+con.getHeaderField(header)); WTv\HI2X !
else Y6?mY!
break; <L ( =
} SH$cn,3F8
} ":^ NLBm>5
Xb:BIp!e
h]DECd{
public void splitterStop() Bp{`%86SE
{ JK]tcP
bStop = true; xp8f
} aa%&&
@:QdCG+
jP.b oj_u*
} z/&a\`DsU
J}_Dpb[L
/A))"D
/* |-Esc|J(
**FileAccess.java S}Y|s]6
*//文件访问(定位，写) Sc$8tLDLj
package NetFox; ?&<o_/`-H5
import java.io.*; <eFAI}=s
DcR}pQ(e
$#ju?B~
public class FileAccessI implements Serializable{ l8AEEG8>
eGSp(o56
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dGD^op,6g
RandomAccessFile oSavedFile; /b:t;0G
long nPos; CndgfOF
K_+;"G
5H:~6z
public FileAccessI() throws IOException mV*/zWh_
{ 71/m.w
this("",0); }B9~X
} MjXE|3&
hKZ`DB4
L}jF#*Q%
public FileAccessI(String sName,long nPos) throws IOException y-\A@jJC5
{ _:Jp*z
oSavedFile = new RandomAccessFile(sName,"rw"); %X"m/4c8}
this.nPos = nPos; #;"D)C
oSavedFile.seek(nPos); 5%Oyvt]}2
} 4`U0">gY
pba8=Z
h#m:Y~GoF
public synchronized int write(byte[] b,int nStart,int nLen) I' ! r
{ VwOG?5W/
int n = -1; 4de]?#=
try{ %`?;V;{=
oSavedFile.write(b,nStart,nLen); bKuj po6
n = nLen; 8L-4}!~C
} 6vgBqn[
catch(IOException e) *|k;a]HT
{ $' (QTEM
e.printStackTrace (); IObx^N_K
} 6 tc:A5mK
GjeUUmr
C1T=O
return n; ',JrY)
} &v$,pg%-:
?jri!]ux#
\+iu@C
} Gg9VS&VI
os1?6z~
Pknc[h},
/* % Cu.u)/+
**SiteInfoBean.java T0`"kjE
*/ iUIy,Y
package NetFox; a#+>w5
wqlcLIJPR
20UqJM8Ot
public class SiteInfoBean { q]6_rY.
Y5ogi)
4l&"]9D
private String sSiteURL; //Site's URL IS[Vap:
private String sFilePath; //Saved File's Path Q !9HA[Ly
private String sFileName; //Saved File's Name %5JW<9
private int nSplitter; //Count of Splited Downloading File v@8S5KJ
e(yQKwVD
q*6q}s3n
public SiteInfoBean() tu\mFHvlg
{//nSplitter的缺省值为5 A7k'K4
//default value of nSplitter is 5 ^ <qrM
this("","","",5); vd}*_d
} Tu]&^[B('
NJZXs_%>$
-uWKY6 :5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R? O-x9
{ M h`CP
sSiteURL= sURL; NSw<t9Yi
sFilePath = sPath; [2Iau1<@
sFileName = sName; _6;<ow
this.nSplitter = nSpiltter; ht?CHUu
/b.$jnqL
o2DtCU-A
} ezp<@'0ZT
n`]l^qE
_=ugxL #eB
public String getSSiteURL() Bn\l'T
{ tG/aH%4S
return sSiteURL; QwBXlO?
} n ]w7Zj
|U#DUqw
;4,'y
public void setSSiteURL(String value) b\?3--q
{ @7-=zt+f
sSiteURL = value; W9dYljnZ8i
} t\8&*(&3F
5.wiTy
RcQ>eZHl
public String getSFilePath() ?0{yq>fTu
{ G*B$%?n
return sFilePath; V]rhVMA
} ?w*yW;V`
vv &BhIf3
iNQ0p:<k
public void setSFilePath(String value) &pM'$}T*
{ `)$`-Pw*
sFilePath = value; NvQ%J+
} H'EY)s Hi
~AQ>g#|%
Nsn~@.UuSW
public String getSFileName() e2c1pgs&+
{ >B_n/v3P(M
return sFileName; CZY7S*fL
} ZHCr2^w6
qK?$=h.
K#!X><B'
public void setSFileName(String value) >Q=Ukn;k
{ zI^Da!r.
sFileName = value; dCeX}Z
} ]dG\j^e|
'a#mViPTQ)
03([@d6<E
public int getNSplitter() h*3{6X#(/
{ _ij$f<
return nSplitter; F~6#LT
} <'+ %\
%v{1#~u
ZB[k{Y
public void setNSplitter(int nCount) 6):Xzx,
{ a }'->H
nSplitter = nCount; G 4qy*.
} (?3[3w~
} ka/XK[/'
5wT>N46UX
26L~X[F
/* Dx-KMiQ,"(
**Utility.java C!&y
*/ >$H|:{D
package NetFox; ;:mu}
O'$K],=BS
L9FHgl?
public class Utility { lw[e*q{s.
Kesy2mE
?WpenUWk
public Utility() _Mt Qi
{ Bs8[+Ft5
(qBvoLkF9N
347eis'
} 4woO;Gm
AIRr{Y
//线程睡眠 yGj.)$1},@
public static void sleep(int nSecond) Xsuwa-G!5~
{ nfdq y)
try{ 'dJ/RJ~
Thread.sleep(nSecond); *7$P]
} u~1o(Zn =
catch(Exception e) feX^~gM
{ iv&v8;B
e.printStackTrace (); E9}{1A
} MYLsHIPC
} e3(/qMl
p$E8Bn%[
//日志 g(ogXA1
public static void log(String sMsg) atF?OP|{,w
{ ds:->+o
System.err.println(sMsg); TDtAmk
} T=Z.TG|lIx
`ln1$
58V[mlW)O0
public static void log(int sMsg) )ChqATKg
{ 'gso'&Uaj
System.err.println(sMsg); ^aZAw%K
} "xJ0 vlw
} TX [%(ft
%A/_5;PZ/
vZj`|
/* I5m][~6.?
**TestMethod.java I=DxRgt
*/ V5f9]D
package NetFox; .L6Zm U
Zw1U@5}A
O$u"/cwe*
public class TestMethod { (la[KqqCO
_~u2: yl(
5Por "&%
public TestMethod() ~]C%/gEh
{ ///xx/weblogic60b2_win.exe aGZi9O7G}
try{ 8;14Q7,S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k^"bLf(4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cTTW06^
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4QOEw-~w&s
fileFetch.start(); PxS4,`#~
} BQH}6ueZ
catch(Exception e){e.printStackTrace ();} $Fkaa<9;P
#|GSQJ$F)`
|*/[`|*G
} )rW&c-'
r}#\BbCv;7
5irwz4.4
public static void main(String[] args) Q6gt+FKU9
{ FTc.]laO
new TestMethod(); YOr:sb
} x<Vm5j
} X$%4$
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