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)); _P5P(^/
} 8A{6j
for(int i=0;i<nEndPos.length-1;i++) 7X'y>\^w^>
{ .ECHxDp
nEndPos = nStartPos[i+1]; !R:y'Y%j
} 2u:4$x8
nEndPos[nEndPos.length-1] = nFileLength; -<W2PY<
} m0( E kK
} ,{{SI
dr})-R
$']VQ4tZ
//启动子线程 40K2uT{cq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =n0*{~r
for(int i=0;i<nStartPos.length;i++) -(;LQDG |
{ /EFq#+6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c8DZJSO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `ROEV~
nStartPos,nEndPos,i); Dip*}8$o(w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WC-_+9)2&
fileSplitterFetch.start(); n33kb/q*
} U9ZbVjqv@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H_B~P%E@]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =!<G!^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mG(N:n%*K
nEndPos = " + nFileLength); kRot7-7I|
// fileSplitterFetch[nPos.length-1].start(); +d39f-[
:vQM>9l7
0Nr\2|
//等待子线程结束 WE.Tuo5L
//int count = 0; 5$Kf]ZP
//是否结束while循环 T*P+Fh"
boolean breakWhile = false; _#'9kx|)
oR %agvc^^
JTUNb'#RZ
while(!bStop) NWKi ()nA%
{ :ba/W&-d
write_nPos(); eXzXd*$S
Utility.sleep(500); '_o@VO
breakWhile = true; *not.2+
V}9;eJRvw
s4t0f_vj`
for(int i=0;i<nStartPos.length;i++) E`AYee%l
{ 3N<&u
if(!fileSplitterFetch.bDownOver) }kPVtSQ
{ ;CmOsA,1
breakWhile = false; 4lz{G*u
break; J{~Rxa
} 9S1#Lr`r
} hC>wFC
if(breakWhile) - ]Y wl
break; 6k9LxC:M
UqtHxEI%R~
/`+7_=-
//count++; h4 vm{ho
//if(count>4) ~:2K#q5C
// siteStop(); 8:{q8xZ=k
} tWk{1IL
zM59UQU;
abWl ut
System.err.println("文件下载结束！"); Sdc*rpH"(
} Yx1 D)
catch(Exception e){e.printStackTrace ();} `-O=>U5nH
} 2R`u[
?,% TU&Yn
0Q1/n2V
//获得文件长度 (=JueF@J
public long getFileSize() ( u f5\}x
{ kaFnw(xa
int nFileLength = -1; 9#@Zz4Ww
try{ IVteF*8hU
URL url = new URL(siteInfoBean.getSSiteURL()); ,F:=(21
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (~#G'Hd
httpConnection.setRequestProperty("User-Agent","NetFox"); }1m_o@{3P
"{( [!
( V4G<-jG
int responseCode=httpConnection.getResponseCode(); O5-;I,)H
if(responseCode>=400) (,LL[&;:
{ 'F5)ACA%
processErrorCode(responseCode); :]c=pH
return -2; //-2 represent access is error F<r4CHfh;
} ;r!\-]5$
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0&$xX!]
String sHeader; Gvn: c/m;
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l0`'5>
for(int i=1;;i++) Mi74Xl i
{ QymD-A"P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O71BM@2<
//Utility.log(in.readLine()); s.y}U5Ty?P
sHeader=httpConnection.getHeaderFieldKey(i); g1qi\axm
if(sHeader!=null) 8]C1K Zs
{ 7) 0q--B
if(sHeader.equals("Content-Length")) 2U%qCfh6|
{ b1=pO]3u
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S=O$JP79
break; Wz{%"o
} !K\itOEP-
} v3^t/[e~:
else H[BYE
break; C*G/_`?9
} *Sb2w*c>
} fuyl/bx}
catch(IOException e){e.printStackTrace ();} KjYDFrR4
catch(Exception e){e.printStackTrace ();} ,?y7,nb
HRHrSf7
D rTM$)
Utility.log(nFileLength); c[{UI
a: IwA9!L
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return nFileLength; gj;@?o0
} wOcg4HlW
)E`+BH
':sTd^V
//保存下载信息（文件指针位置） P)IjL&[
private void write_nPos() b~as64
{ ;[~^(. f
try{ xBWx+My
output = new DataOutputStream(new FileOutputStream(tmpFile)); UE7'B?
output.writeInt(nStartPos.length); w `!LFHK
for(int i=0;i<nStartPos.length;i++) `,Zb2"
{ g)cY\`&W8
// output.writeLong(nPos); } J(1V!EA
output.writeLong(fileSplitterFetch.nStartPos); ]ymC3LV]
output.writeLong(fileSplitterFetch.nEndPos); .K7C-Xn=
} 6Ahr_{
output.close(); 7TdQRB
} 0||F`24
catch(IOException e){e.printStackTrace ();} Ilef+V^qr
catch(Exception e){e.printStackTrace ();} p`p?li
} k<Oy%+C
%M6 c0d[9-
C8MWIX}
//读取保存的下载信息（文件指针位置） jGiw96,Y
private void read_nPos() 4:`[qE3
{ raHVkE{<
try{ 2Oi'E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); % $.vOFP9
int nCount = input.readInt(); $_bZA;EMQ
nStartPos = new long[nCount]; $rTu6(i1
nEndPos = new long[nCount]; DZP*x
for(int i=0;i<nStartPos.length;i++) GBr,LN
{ -t>Z 9
nStartPos = input.readLong(); )JX$/- RD-
nEndPos = input.readLong(); hr1$1&p
} .qinR6=
input.close(); 9A<0zt
} mt^`1ekoY
catch(IOException e){e.printStackTrace ();} \!4|tBKVY
catch(Exception e){e.printStackTrace ();} cD8Ea(
} @T/qd>T o
GEfY^!F+
U2UyN9:6F
private void processErrorCode(int nErrorCode) -p^'XL*Z
{ P'F~\**5
System.err.println("Error Code : " + nErrorCode); g8v[)o(qd
} P4[]qbfd,
`:gYXeR
yU!GS-
//停止文件下载 {\Ys@FF
public void siteStop() @E(P9zQ/zy
{ V" }*"P-%
bStop = true; 6lZGcRO
for(int i=0;i<nStartPos.length;i++) }Az'Zu4 =
fileSplitterFetch.splitterStop(); z \^
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N-Z^G<[q.
} ,\}k~ U99
} ()B7(Y
//负责部分文件的抓取 ) H+d.Y
**FileSplitterFetch.java ETg{yBsp
*/ HSC6;~U
package NetFox; Tplg2p%k
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H\d;QN9Q;
import java.io.*; kw#X]`c3
import java.net.*; AbG&9=Ks
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[tz u;/
public class FileSplitterFetch extends Thread { u]SZ{[e
90(UgK&Y
V:8@)Hc=
String sURL; //File URL jf8w7T
long nStartPos; //File Snippet Start Position kAt RY4p
long nEndPos; //File Snippet End Position GqMB^Ad
int nThreadID; //Thread's ID L^x5&CCwk
boolean bDownOver = false; //Downing is over FXxN>\76.
boolean bStop = false; //Stop identical UtPwWB_YV
FileAccessI fileAccessI = null; //File Access interface L, #Byao
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hWm0$v1p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $i -zMa
{ df yrn%^Ia
this.sURL = sURL; #XfT1
this.nStartPos = nStart; Yq{jEatY{/
this.nEndPos = nEnd; &rcdr+'
nThreadID = id; s4N,^_j
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xlk5Gob*
} ;8uHRcdQ
E;$$+rA
]y}Zi/zh
public void run() :k\}Ik
{ r;$r=Ufr
while(nStartPos < nEndPos && !bStop) /0-\ek ye
{ }\EL;sT
lZBv\JE
Gg}t-_M
try{ xmOM<0T
URL url = new URL(sURL); 1j+eD:d'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \:h0w;34O
httpConnection.setRequestProperty("User-Agent","NetFox"); Eh:yRJ_8
String sProperty = "bytes="+nStartPos+"-"; :Nkz,R?
httpConnection.setRequestProperty("RANGE",sProperty); &D^e<j}RQ
Utility.log(sProperty); 8a?IC|~Pz
i"<ZVw
Pm~,Ky&Hl
InputStream input = httpConnection.getInputStream(); `{Hb2 }L5
//logResponseHead(httpConnection); C!hXEtK
d;<.;Od$`
$.;iu2iyo
byte[] b = new byte[1024]; K(' 9l& A
int nRead; vWuyft*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'Z y{mq\
{ ~RAzFLt6x
nStartPos += fileAccessI.write(b,0,nRead); $Q=$?>4U
//if(nThreadID == 1) :ET x*c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8pd&3G+
} k~& o
v,8Si'"i+
kF#{An)P
Utility.log("Thread " + nThreadID + " is over!"); M*v^N]>"G
bDownOver = true; y _6r/z^
//nPos = fileAccessI.write (b,0,nRead); 9Il'E6 J
} =#jTo|~u4o
catch(Exception e){e.printStackTrace ();} [+_\z',u
} } mgVC
} aE}=^%D
\;iG{}(
KLON;
//打印回应的头信息 Z`|>tbOfZ
public void logResponseHead(HttpURLConnection con) 2UQN*_
{ ,=yOek}
for(int i=1;;i++) W%=Zdm rv
{ 3F;EE:
String header=con.getHeaderFieldKey(i); [1e.i
if(header!=null) $x/J+9Ww
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3Sk5I%
Utility.log(header+" : "+con.getHeaderField(header)); EkDws`@
else GpScc'a7
break; wE)] ah:
} )7tV*=?Ic8
} e<kpcF5{\
XadG\_?t`
.[#xQ=9`
public void splitterStop() K6ciqwUO
{ YcPKM@xo
bStop = true; \m@]G3=]
} /FoUo
D\@e{.$MZ|
$#D n4
} cn@03&dAl
c]S+70!n
U<K|jsFo
/* *Rz!i m|
**FileAccess.java jQO*oq}
*//文件访问(定位，写) 0kkRK*fp}x
package NetFox; '9f6ZAnYpQ
import java.io.*; 7sCR!0
o7m99(
l# }As.o}
public class FileAccessI implements Serializable{ :PHUsy
`^?}s-H+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nZ"{y
RandomAccessFile oSavedFile; y?[5jL|Ue
long nPos; pM1=UF
od;Bb
d&O'r[S
public FileAccessI() throws IOException #($k 3OA
{ oXnC"y}0P
this("",0); 5w]DncdQ~
} &19lk
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y>DfM5>
public FileAccessI(String sName,long nPos) throws IOException l~`txe
{ K(%dcUGDK>
oSavedFile = new RandomAccessFile(sName,"rw"); 4x=V|"
this.nPos = nPos; Pn~pej5'K
oSavedFile.seek(nPos); 8XLxT(YFIs
} Y:DNu9
.CIbpV?T
3L'en
public synchronized int write(byte[] b,int nStart,int nLen) >lUBt5gU
{ n$XMsl.>
int n = -1; 1EKcD^U,
try{ aeN}hG
oSavedFile.write(b,nStart,nLen); 9:bh3@r/
n = nLen; nF|#@O`1
} #j(q/ T{x
catch(IOException e) tI/mE[W
{ x.jYip
e.printStackTrace (); K0d-MC
} s:-8 Z\,
<B|n<R<?
Z!q2F%02FO
return n; IKNFYe[9e
} Jnh;;<
=;~%L
z^gDbXS
} Dme(Knly
Co{MIuL
Xq=!"E
/* z&>9 s)^-
**SiteInfoBean.java B:R7[G;1
*/ _ Yb Eo+
package NetFox; #u}v7{4
.0R/'!e
9,Crmbw8
public class SiteInfoBean { @lb=-oR!~
pgLzFY['
>S?C {_g
private String sSiteURL; //Site's URL PCV58n3
private String sFilePath; //Saved File's Path 8GF[)z&|P:
private String sFileName; //Saved File's Name 3B!&ow<rt
private int nSplitter; //Count of Splited Downloading File UUdu;3E=5
$sd3h\P&R
];d5X
public SiteInfoBean() i_oro"%yL
{//nSplitter的缺省值为5 ;-Y]X(z>
//default value of nSplitter is 5 mh!N^[=n
this("","","",5); g:~?U*f-
} ?~]1Gd
.N-'; %8
nzQYn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |k['wqn"
{ YoSo0fQA
sSiteURL= sURL; !Vp,YN+yN
sFilePath = sPath; ^C,/T2>
sFileName = sName; [0**&.obz
this.nSplitter = nSpiltter; _D7HQ
H3UX{|[
o2 T/IJP
} 7Ap~7)z[
XNkQk0i;g&
vV:MS O'r
public String getSSiteURL() WwCK K
{ LX(iuf+l
return sSiteURL; 4z-,M7iP
} 8JjU 9#
^t/'dfF
`a/PIc"
public void setSSiteURL(String value) 1drqWI~
{ WIH4Aw
sSiteURL = value; fY,@2VxyfA
} OI]K_ m3
IgHs&=
61s2bt#
public String getSFilePath() ZH`K%h0
{ *`S)@'@:(
return sFilePath; rlUdAa3
} K[Egwk7
buCm @@o
5m%baf2_
public void setSFilePath(String value) alb+R$s
{ ]"2 v7)e
sFilePath = value; 3-_U-:2"
} <L!~f`nH2
U4^p({\|-
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public String getSFileName() \^;|S
{ Dbkuh!R
return sFileName; sBuq
} SG+i\yu$h0
q.,p6D
\/x)BE,
public void setSFileName(String value) 6ljRV)
{ ELkOrV~a{:
sFileName = value; 0]2B-o"kI
} HhY2`P8
;f ;*Q>!
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public int getNSplitter() xP5mL3j
{ ;+TF3av0zq
return nSplitter; J?n)FgxS
} [-:<z?(n4
&\6`[# bT
} {gWTp
public void setNSplitter(int nCount) 3>@qQ_8%~
{ _?(hWC"0
nSplitter = nCount; }Nd`;d
} >m_p\$_
} ;SlS!6.W-
jN'fm
t\|K"
/* asmW W8lz
**Utility.java abJ@>7V
*/ 3qxG?G N
package NetFox; jFPE>F7-M
F)<G]i8n~
h2/1S{/n]
public class Utility { hOrk^iYN=
+k(3+b$S-
9^ *ZH1
public Utility() ~a8G 5M
{ 5S-o 2a
Pguyf2/w
ixJ20A7
} +v[$lh+
Oz9Mqcx
//线程睡眠 eI=Y~jy
public static void sleep(int nSecond) ?C>VB+X}y
{ m^oi4mV
try{ n.8A Ka6
Thread.sleep(nSecond); T>uWf#&pjs
} Uc4L|:
catch(Exception e) @IyH(J],h
{ }^Ua
e.printStackTrace (); <{z3p:\
} !Bd* L~D
} CXP $bt}
Q3'B$,3O^
//日志 M;TfD
public static void log(String sMsg) "JUQ)> !?
{ tm36Lw
System.err.println(sMsg); !K^Z5A_;
} s*~jvL
:Z]+Z_9p
)zLS,/pk^
public static void log(int sMsg) f w>Gx9
{ M_.,c Vk
System.err.println(sMsg); }$k`[ivBx(
} eze(>0\f
} ]R0A{+]n
t1{%FJ0F
Qpv}N*v^
/* f$S QhK5`
**TestMethod.java W!4V:(T
*/ W.6JnYLQ&
package NetFox; >~wk
3f2Hjk7,d
Z"%O&O
public class TestMethod { ;R|#ae@
~:b:_ 5"
$8T|r+<
public TestMethod() r dG2| Tp
{ ///xx/weblogic60b2_win.exe <iprPk
try{ D15u1A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _d=&9d#=\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ://# %SE
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]E8<;t)#
fileFetch.start(); 6RT0\^X*:
} >\oJ&gdc
catch(Exception e){e.printStackTrace ();} I&NpN~AU
!%\To(r[
$Ex 9
} zf;[nz
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public static void main(String[] args) [Fj#7VZK
{ >8fz ?A
new TestMethod(); L9YwOSb.
} k| cI!
} 3(GrDO9^
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