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)); '/M9V{DD88
} Wd"<u2
for(int i=0;i<nEndPos.length-1;i++) :0N}K}
{ VZuluV
nEndPos = nStartPos[i+1]; !*Ex}K99
} E| eEAa
nEndPos[nEndPos.length-1] = nFileLength; Rr#Zcs!G
} ZD!?mR+-
} q_iPWmf p*
X)7_@,7
!2L?8oP-z
//启动子线程 N~NUBEKcp
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9#(Nd, m})
for(int i=0;i<nStartPos.length;i++) *{WhUHZF
{ SFqY*:svOw
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8R|!$P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h;" 9.
nStartPos,nEndPos,i); C\2rSyo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x6yYx_
fileSplitterFetch.start(); NzS(,F
} pGZiADT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZtHTl\z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]q^6az(Ud
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >s dT=6v
nEndPos = " + nFileLength); K(jo[S
// fileSplitterFetch[nPos.length-1].start(); k7,
<|-da&7
|WP}y-Au
//等待子线程结束 T'6MAxEZUq
//int count = 0; U80h0t%
//是否结束while循环 ;f?suawMv
boolean breakWhile = false; KBC?SxJSJc
5aZbNV}-
LX'z7fh
while(!bStop) X,xCR]+5S
{ nh XVc((
write_nPos(); uH{oJSrK
Utility.sleep(500); IL>VH`D
breakWhile = true; Wn%b}{9Fb
X'uQr+p^
;_X2E~i[
for(int i=0;i<nStartPos.length;i++) J7;8 S
{ 0SjB&J
if(!fileSplitterFetch.bDownOver) y5{Vx{V"Q
{ &J?:wC=E
breakWhile = false; LvqWA}
break; Ce/l[v
} sOJXloeO[6
} @WCA7DW!
if(breakWhile) Z% DJ{!Hnh
break; jd`h)4
OwCbv j0#
}el7@Gv
//count++; 5,R4:y ?cK
//if(count>4) ~^TH5n
// siteStop(); 6H1;Hl f
} nIr:a|}[
N:q\i57x
eo*l^7
System.err.println("文件下载结束！"); D7r&z?
} W)Ct*I^
catch(Exception e){e.printStackTrace ();} h% eGtd$n
} M5a&eO
u69UUkG
_\.4ofK(
//获得文件长度 P;`Awp?
public long getFileSize() < 1%}8t"
{ K491QXG
int nFileLength = -1; 5Gs>rq" #
try{ d6a3\f
URL url = new URL(siteInfoBean.getSSiteURL()); Xs{PAS0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IH&0>a
httpConnection.setRequestProperty("User-Agent","NetFox"); +%f6{&q$
?b:Pl{?
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int responseCode=httpConnection.getResponseCode(); hVz] wKP
if(responseCode>=400) %JHv2[r^P
{ 3G[|4v?[<_
processErrorCode(responseCode); Z3yy(D>*
return -2; //-2 represent access is error t`="2$NO
} Q6HghG
&09&;KJ
!Rc %
String sHeader; -u(,*9]cJ*
Gy[anDE&
et/:vLl13
for(int i=1;;i++) Ab]tLz|Z
{ {sf ,(.W
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gD51N()s,
//Utility.log(in.readLine()); 41]a{A7q
sHeader=httpConnection.getHeaderFieldKey(i); SXP(C^?C
if(sHeader!=null) s1E 0atT
{ Yn[>Y)
if(sHeader.equals("Content-Length")) /* qx5$~
{ -b iE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cxQAp
break; nw\C+1F
} +SF+$^T
} I`(53LCqo
else ImG8v[Q E
break; &TY74w*
} Z1jxu;O(
} KJV8y"^=Q
catch(IOException e){e.printStackTrace ();} 2GORGS%
catch(Exception e){e.printStackTrace ();} xVw@pR;
=}%#j0a4
1I`F?MT
Utility.log(nFileLength); aoZ|@x
@!=Ds'MJC
I5q$QQK
return nFileLength; #2s}s<Sc;
} D{s87h
rH!sImz,
$cIaLq
//保存下载信息（文件指针位置） y%ij)vQY
private void write_nPos() E& .^|<n
{ (BPO*'
try{ ,{!,%]bC
output = new DataOutputStream(new FileOutputStream(tmpFile)); "o+?vx-
output.writeInt(nStartPos.length); haBmwq(f
for(int i=0;i<nStartPos.length;i++) C{}PO u
{ QK?V^E
// output.writeLong(nPos); Nd]F 33|X
output.writeLong(fileSplitterFetch.nStartPos); '=vZAV`
output.writeLong(fileSplitterFetch.nEndPos); `@ YV
} d_d&su E
output.close(); L~-/'+
} 'bJGQ[c
catch(IOException e){e.printStackTrace ();} A[uE#T^
catch(Exception e){e.printStackTrace ();} !DzeJWM|
} t*9 gusmG
{iX#
m{Vd3{H40
//读取保存的下载信息（文件指针位置） ~w3u(X$m"
private void read_nPos() ~*7$aj
{ }ofb]_C,
try{ #Z1-+X8P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); LWv<mtuYf
int nCount = input.readInt(); @>Yd6C
nStartPos = new long[nCount]; M i& ;1!bg
nEndPos = new long[nCount]; A|8"}Hm
for(int i=0;i<nStartPos.length;i++) salC4z3
{ F*[E28ia&
nStartPos = input.readLong(); "G [Nb:,CR
nEndPos = input.readLong(); ;:D-}t;
} -y-}g[`
input.close(); _K9`o^g%PJ
} RFL* qd4
catch(IOException e){e.printStackTrace ();} x|a&wC2,{
catch(Exception e){e.printStackTrace ();} OW@%H;b
} q13fmK(n-5
KMwV;r
3_)I&RM
private void processErrorCode(int nErrorCode) MvpJ0Y (
{ D_d>A+
System.err.println("Error Code : " + nErrorCode); t|iNSy3
} G`zNCx.
4C=W~6~
^wolY0p
//停止文件下载 d <}'eBT'
public void siteStop() rJ Jx8)M
{ Ab ,^y
bStop = true; H ni^S
for(int i=0;i<nStartPos.length;i++) L*Z.T^h
fileSplitterFetch.splitterStop(); 8X7??f1;Y
_/LGGt4&%
RxMsP;be
} G1z*e.+y
} &YXJ{<s
//负责部分文件的抓取 309 pl
**FileSplitterFetch.java &IQ=M.!r
*/ ;\*3A22 #
package NetFox; 0$)Q@#
m=01V5_
3%+~"4&
import java.io.*; 45c?0tj
import java.net.*; \P.h;|u
TN0KS]^A3
cX-M9Cz
public class FileSplitterFetch extends Thread { 4f\NtQ)
^!1!l-
&'z_:Wm
String sURL; //File URL gyvrQ, u
long nStartPos; //File Snippet Start Position 5.6tVr
long nEndPos; //File Snippet End Position N[/<xW~x?4
int nThreadID; //Thread's ID Ks%0!X?3q
boolean bDownOver = false; //Downing is over 1tNL)x"w
boolean bStop = false; //Stop identical 3NpB1lgh&:
FileAccessI fileAccessI = null; //File Access interface &!8 WRJ
DC8#b`j
*C*ZmC5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZQfxlzj+X
{ 6j6CA?|
this.sURL = sURL; gI^&z
this.nStartPos = nStart; jaoZ}}V_$
this.nEndPos = nEnd; -+WAaJ(b
nThreadID = id; EwPrh
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p1KhI;^
} -8n1y[
[9">}l
!zE{`Ha~
public void run() ~~/,2^
{ OXQ*Xpc
while(nStartPos < nEndPos && !bStop) bB_LL
{ 40kAGs>_
o'DtW#F
MRLiiIrq,5
try{ ztO)~uL
URL url = new URL(sURL); M/<ypJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O)dnr8*
httpConnection.setRequestProperty("User-Agent","NetFox"); /z-rBfdy^
String sProperty = "bytes="+nStartPos+"-"; uFWA] ":is
httpConnection.setRequestProperty("RANGE",sProperty); ZsP^<
Utility.log(sProperty); ]U>MYdGWb
v,-Tk=qP
.RxTz9(
InputStream input = httpConnection.getInputStream(); {xTq5`&gT
//logResponseHead(httpConnection); &nmBsl3Q.
#p(gB)o:l
rbd0`J9fq
byte[] b = new byte[1024]; ,XT,t[w
int nRead; R (f:UC
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TUp\,T^2
{ .\XRkr'-
nStartPos += fileAccessI.write(b,0,nRead); Ux_tzd0!
//if(nThreadID == 1) `PUqz&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N'2?Zb
} E/:U,u{
lju5+0BSb
zb0NqIN:
Utility.log("Thread " + nThreadID + " is over!"); |nQfgl=V
bDownOver = true; Lvf<g}?4
//nPos = fileAccessI.write (b,0,nRead); .V;,6Vq
} 1`8s "T
catch(Exception e){e.printStackTrace ();} @D9O<x
} j e\!0{
} 0C<\m\|~k
fJLl-H
tiZH;t';<
//打印回应的头信息 n5QO'Jr%[
public void logResponseHead(HttpURLConnection con) 3/RwCtc
{ #*A&jo'E
for(int i=1;;i++) S|=)^$:
{ <f7 O3 >
String header=con.getHeaderFieldKey(i); :I#.d7`uk
if(header!=null) %B@NW2ZQ[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *B&P[n
Utility.log(header+" : "+con.getHeaderField(header)); sV"tN2W@
else q[Ai^79
break; }%XB*pzQ
} m'2F#{
} phDIUhL$z
' #K@%P
^y>V-R/N
public void splitterStop() O<vBuD2
{ t]&.'n,
bStop = true; Oem1=QpaC
} +Ug &
F>.y>h
e,sS.
} G4i%/_JU
^?e[$}
fS}Eu4Xe
/* 0@_8JB ?E
**FileAccess.java 7O)ATb#up
*//文件访问(定位，写) A6szTX#0
package NetFox; 1'~+.92Y
import java.io.*; g(P7CX+y
1 k!gR
,q*|R O
public class FileAccessI implements Serializable{ (B` NnL$
ywm"{ U?8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xDe^>(,"
RandomAccessFile oSavedFile; =F[M>o
long nPos; v_5O*F7)
!o| ex+z;
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public FileAccessI() throws IOException =)y$&Ydj
{ UVXruH
this("",0); >%"TrAt
} e`+
CV|Ae [
h(2{+Y+
public FileAccessI(String sName,long nPos) throws IOException .dzw5R&
{ 1mgw0QO
oSavedFile = new RandomAccessFile(sName,"rw"); ft8
this.nPos = nPos; >o"s1* {
oSavedFile.seek(nPos); o ^w^dgJ
} 2s2KI=6
Iv7BIK^0
;Qd'G7+
public synchronized int write(byte[] b,int nStart,int nLen) <mLU-'c@
{ "QfF]/:
int n = -1; jhG6,;1zMI
try{ !/2kJOSp
oSavedFile.write(b,nStart,nLen); 7OZ0;fK
n = nLen; }`whg8 fZ
} Pd:tRY+t/
catch(IOException e) Uwiy@T Z
{ aS3-A4
e.printStackTrace (); cL%eP.
} a6T!)g
99h#M3@!
$v{sb,
return n; MMRO@MdfV
} 1iY?t
O6-"q+H)
}LBrk0]
} <Dnv=)Rq
#$t93EI
tV.96P;)/9
/* IOUzj{G#
**SiteInfoBean.java nNM)rW
*/ Z;U\h2TY
package NetFox; 'vIVsv<p
imS&N.*3m
QZ-6aq\sgp
public class SiteInfoBean { %cc<>Hi
xJzO?a'
j|% C?N
private String sSiteURL; //Site's URL fwyz|>H_Y(
private String sFilePath; //Saved File's Path Jxb+NPUB
private String sFileName; //Saved File's Name fl9J
private int nSplitter; //Count of Splited Downloading File 0.Nik^~
`WU"*HqW
Q5v_^O<!
public SiteInfoBean() :'dH)yO
{//nSplitter的缺省值为5 $ "^yoL
//default value of nSplitter is 5 0wl31k{
this("","","",5); DCtrTX
} l3/?,xn
EEp,Z`
qxwD4L`S
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cbA90 8@s
{ W[W}:@KZ
sSiteURL= sURL; n47v5.Wn
sFilePath = sPath; &@D,|kHk
sFileName = sName; 3m`y?Dd
this.nSplitter = nSpiltter; |N>TPK&Xt
&mvC<_1n
)![?JXf
} [<{+tAdn)
V5LzUg]
M>g\Y
public String getSSiteURL() tm}0kWx
{ >H?{=H+/#
return sSiteURL; UYb:q
} F4Gv=q)Z
5Y97?n+6
P\CT|K'P
public void setSSiteURL(String value) B[O1^jdO
{ `H6kC$^Ofx
sSiteURL = value; Hi<5jl
} (a i&v
}A%Sx!7~
T/&4lJ^2l^
public String getSFilePath() H?>R#Ds-
{ + >oA@z
return sFilePath; x;Jy-hMNl
} ^i^/d#
=X11x)]F9
sc^TElic
public void setSFilePath(String value) 3X&}{M:Qo
{ Xo>P?^c4?
sFilePath = value; =q(;g]e
} 4` gAluJ#
>8nRP%r[5,
w#5^A(NR
public String getSFileName() Vx^+Z,y&QP
{ _s Z9p4]
return sFileName; 8`*Wl;9u
} 8rXu^
7N/v
h$FpH\-
public void setSFileName(String value) ^[SQw)*
{ dhW)<
sFileName = value; LuB-9[^<
} wTGH5}QZ+
@O/-~,E68
\4`~J@5Y
public int getNSplitter() eEkFZx
{ gh3XC.&
return nSplitter; u|.L73<j%
} 8M;VX3X
wvum7K{tI
Lmx95[#@a
public void setNSplitter(int nCount) w^?uBeqR
{ ++Qg5FukR
nSplitter = nCount; C&b^TLe
} SNB>
} ^9 gFW $]
y-gSal
#`rvL6W q}
/* s88lN=;
**Utility.java n5X0Gi9
*/ j_VTa/
package NetFox; "If]qX(w
5 iUT#
#8G(r9
public class Utility { sG`:mc~0
&y/
U)%gzXTZ%
public Utility() 3zU!5tg
{ sHx>UvN6
wiXdb[[#
vq|o}6Et
} 7{ zkqug
Mvq5s+.
//线程睡眠 `x2Q:&.H`
public static void sleep(int nSecond) fX=o,=-f
{ 2`qO'V3Q
try{ PMzPe"3M
Thread.sleep(nSecond); )# le|Rf
} j^ VAA\
catch(Exception e) rnvKfTpZDU
{ 1@*qz\ YY
e.printStackTrace (); dGU io?
} X#KC<BXw,
} e"9u}-Q@
:feU
//日志 n4Od4&r
public static void log(String sMsg) 4<b=;8
{ #jAlmxN
System.err.println(sMsg); +.gM"JV
} :=qblc
eYd6~T[9
qP6YnJWl
public static void log(int sMsg) `NqX{26GV+
{ VPG+]>*
System.err.println(sMsg); 0Q^ -d+!
} %a-*Ku
} 0'T*l2Z`2
+L(0R&C
ck-ab0n
/* oG5:]/F
**TestMethod.java ?+{=>{1
*/ oxkA+}^j8M
package NetFox; [J4 Aig
d~B]s
gd~# uR\
public class TestMethod { bvZTB<rA
~Q7)6%
TEC'}%
public TestMethod() "vVL52HwB
{ ///xx/weblogic60b2_win.exe ?M'_L']N[
try{ bo^d!/;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); n{oRmw-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .yp"6S^b
SiteFileFetch fileFetch = new SiteFileFetch(bean); E[N5vG<
fileFetch.start(); ,0ZkE}<=w
} =/xTUI4
catch(Exception e){e.printStackTrace ();} ^zjQ(ca@"x
q}Wd`>VDR
2w>lnJ-
} Gt{'` P,&9
xsjJ8>G
}2qmL$
public static void main(String[] args) Yv0;UKd
{ 5X^bvW26
new TestMethod(); !_{2\&
} Vg1! u+`<
} )3O0:]<H
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