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)); 5DUPsV
} df rr.i
for(int i=0;i<nEndPos.length-1;i++) 3AL=*qq
{ Q>*K/%KD
nEndPos = nStartPos[i+1]; mpAh'f4$*
} CfnCi_=[`
nEndPos[nEndPos.length-1] = nFileLength; ne*aC_)bT
} O5%F-}(:
} oh~Dbu=%
X0=-{<W
XArLL5_L
//启动子线程 <Y6>L};
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \Rt
for(int i=0;i<nStartPos.length;i++) 41D[[Gh
{ qz2d'OhmtH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TI&J>/z;$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <v^.FxId
nStartPos,nEndPos,i); -e\kIK %
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~WLsqP5Y~a
fileSplitterFetch.start(); &bx,6dX
} _erH]E| [
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9K(b Z{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q:|E
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", emO!6]0gJ
nEndPos = " + nFileLength); H9[.#+ln
// fileSplitterFetch[nPos.length-1].start(); 50`r}s}
cIkLdh
j* ?MFvwE
//等待子线程结束 svgi!=
//int count = 0; qeGOSGc_
//是否结束while循环 T^>cT"ux_
boolean breakWhile = false; #2=30
C`K/ai{4
h UDEjW@S
while(!bStop) r?7^@
{ ~!u94_:
write_nPos(); 2O>iAzc
Utility.sleep(500); `Y9@?s Q
breakWhile = true; ?-i&6i6Y
AU2Nmf?]%
l6O(+*6Us
for(int i=0;i<nStartPos.length;i++) s5@^g8(+C
{ >MLqOUr#
if(!fileSplitterFetch.bDownOver) v\u+=}rl
{ [c~zO+x
breakWhile = false; 0't)fnI#
break; c-{]H8$v
} sj2+|>
} rv>6k:(
if(breakWhile) :PJjy6,1
break; S5M t?v|K
7IRn
VPzdT*g]
//count++; wu3ZSLY
//if(count>4) >d|W>|8e
// siteStop(); 14O/R3+
} Rlu;l
T%F'4_~No
i=rW{0c%
System.err.println("文件下载结束！"); E.brQx#}
} 0jq#,p=l;
catch(Exception e){e.printStackTrace ();} kQtl&{;k?
} F u)7J4Z
J<D =\
3@SfCG&|e
//获得文件长度 yuWrU<Kw
public long getFileSize() ! >V1zk
{ NaIVKo
int nFileLength = -1; 3dfSu'
try{ YjT #^AH
URL url = new URL(siteInfoBean.getSSiteURL()); |RdSrVB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O4{&B@!
httpConnection.setRequestProperty("User-Agent","NetFox"); O1PdM52
[ q}WS5Cp
7O j9~3o4
int responseCode=httpConnection.getResponseCode(); |tkmO:
if(responseCode>=400) ,;g:qe3D$
{ b $!l*r
processErrorCode(responseCode); a+d|9y/k
return -2; //-2 represent access is error BL7%MvDQ
} Vj1AW<
6gn|WO=Wf
mvnK)R_
String sHeader; u]"RAH
n=~?BxB
1RLSeT
for(int i=1;;i++) ! JN@4
{ 0Pe.G0 #
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /TdTo@
//Utility.log(in.readLine()); :Wln$L$
sHeader=httpConnection.getHeaderFieldKey(i); (s*}=
if(sHeader!=null) E^s>S,U[y
{ Nz8iU@!a
if(sHeader.equals("Content-Length")) [(1O_X(M
{ ;:OJQFu%4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |2Dlw]d
break; "D+QT+sD
} +KZc"0?
} iw%DQ }$
else yTk9+>
break; -kkXyO8js
} ZD*>i=S
} g`6S*&8I
catch(IOException e){e.printStackTrace ();} K%;O$ >
catch(Exception e){e.printStackTrace ();} !zeBxR$&o
^^Y0 \3.
IkupW|}rc
Utility.log(nFileLength); x&sF_<[
({)_[dJ'
i ):el=
return nFileLength; m{X;|-DK[
} W* YfyM
;YB8X&H$
r&#q=R},p
//保存下载信息（文件指针位置） ^T"A9uaG
private void write_nPos() >Kxl+F
{ mJ-@:5
try{ {Su]P {oJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); oR~+s&c
output.writeInt(nStartPos.length); jRGG5w}
for(int i=0;i<nStartPos.length;i++) 0\/7[nwS
{ /H)l\m +
// output.writeLong(nPos); )K}b,X`($
output.writeLong(fileSplitterFetch.nStartPos); cWm.']
output.writeLong(fileSplitterFetch.nEndPos); ]uP{Sj
} i^=an?}/
output.close(); f,$FrI,
} %j'lWwi
catch(IOException e){e.printStackTrace ();} #ws6z`mt
catch(Exception e){e.printStackTrace ();} REa%kU
} ?C_%"!GR
6rk/74gI,a
Wd[XQZ<
//读取保存的下载信息（文件指针位置） CNzK-,
private void read_nPos() #SL/Jr DZ
{ #)XO,^s.
try{ d;f,vN(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bf3)^ 49}
int nCount = input.readInt(); 4>(?R[:p)
nStartPos = new long[nCount]; 8F%TZM
nEndPos = new long[nCount]; M 3^p,[9r#
for(int i=0;i<nStartPos.length;i++) g?`w)O7v
{ /8.;
nStartPos = input.readLong(); ;$nK ^
nEndPos = input.readLong(); m^`X|xK-
} D}:D,s8UP
input.close(); SN+&'?$WD
} j,Mp["X&
catch(IOException e){e.printStackTrace ();} 7IHWj<
catch(Exception e){e.printStackTrace ();} _ TUw0:&
} -"<eq0
;e-iiC]PI
L%fWa2P'
private void processErrorCode(int nErrorCode) NvYgRf}uh
{ D4@=+
System.err.println("Error Code : " + nErrorCode); %$b 5&>q
} fY>\VY$>
!\p-|51
KExfa4W 3{
//停止文件下载 A1i-QG/6
public void siteStop() z8A`BVqI
{ qoOHWh&
bStop = true; qWo|LpxWt
for(int i=0;i<nStartPos.length;i++) b\}`L"
fileSplitterFetch.splitterStop(); "|f;
e7<~[>g)
A=BpB}b
} Q&wBX%@^L
} JG4Tb{F=
//负责部分文件的抓取 T `N(=T^*
**FileSplitterFetch.java Xa-]+_?Q
*/ 9gjx!t>`H
package NetFox; tEb2>+R
XfB;^y=u8
X!r!lW
import java.io.*; O#9Q+BD
import java.net.*; h4sEH
xU)~)eK
P||u{]vU
public class FileSplitterFetch extends Thread { >GqIpfn
H.'_NCF&;L
Lc+)#9*d
String sURL; //File URL iTD{
long nStartPos; //File Snippet Start Position /Z\zB
long nEndPos; //File Snippet End Position I_v]^>Xw
int nThreadID; //Thread's ID 1298&C@
boolean bDownOver = false; //Downing is over H3MT.Cpd
boolean bStop = false; //Stop identical S# SA:>8s
FileAccessI fileAccessI = null; //File Access interface N+h|Ffnp
WC}mt%H*O
n_iq85
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vVE^Y
{ ;0@"1`
this.sURL = sURL; \}Hk`n)Aq
this.nStartPos = nStart; b@nbXm]Z
this.nEndPos = nEnd; H,] D}r
nThreadID = id; ;b(/PH!O
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ZN^9w"A
} BC&Et62*
)\p@E3Uxf
*_U z**M
public void run() QD7>S(p
{ DAJh9I
while(nStartPos < nEndPos && !bStop) 'M YqCfIK
{ 2Ask]
-0lpsF
M1VRc[ RRo
try{ S tn[M|
URL url = new URL(sURL); =T;%R^@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )p(XY34]
httpConnection.setRequestProperty("User-Agent","NetFox"); ))u$j4V
String sProperty = "bytes="+nStartPos+"-"; julAN$2
httpConnection.setRequestProperty("RANGE",sProperty); J>x)J}:;
Utility.log(sProperty); 8&H1w9NrX_
Xig%Q~oMp
6]na#<
InputStream input = httpConnection.getInputStream(); bSBI[S
//logResponseHead(httpConnection); ,1QU
CEt_wKzf
&9IMZAo
byte[] b = new byte[1024]; h|_G2p^J+"
int nRead; !dGy"-i$h
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1 BVivEG
{ fH}`
nStartPos += fileAccessI.write(b,0,nRead); m&b!\"0
//if(nThreadID == 1) Q-BciBh$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DH@*Oz-
} P6;L\9=H<
.GLotc
{P(IA2J'S
Utility.log("Thread " + nThreadID + " is over!"); zaR~fO
bDownOver = true; (eG#JVsm9
//nPos = fileAccessI.write (b,0,nRead); 7vgz=- MZ#
} dEns|r
catch(Exception e){e.printStackTrace ();} si0jXue~j\
} XW`&1qx
} ^i#F+Q`1
QfRt3\^`
\Ui8Sgeei
//打印回应的头信息 v:<u0B-)$
public void logResponseHead(HttpURLConnection con) j =[Td
{ g7#_a6
for(int i=1;;i++) ,!PNfJA2
{ dLG5yx\js
String header=con.getHeaderFieldKey(i); 4e1Zyi!
if(header!=null) rQ.j$U
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O zY&^:>
Utility.log(header+" : "+con.getHeaderField(header)); ytr~} M%
else %F1 Ce/
break; 7teg*M{
} 2A {k>TjQ
} KYd2=P6
n+j'FfSz
#W'jNX,h
public void splitterStop() >=[w{Vn'Mf
{ ,]1K^UeZ
bStop = true; !dStl:B
} `QAotSO+
jcv3ES^
:1=mNrg
} Jc:*X4-'
.Mdxbs6.C
D@FJVF7c
/* -i7W|X"
**FileAccess.java 4:5CnK
*//文件访问(定位，写) 315Rk!{AJ
package NetFox; YM/^-[k3
import java.io.*; @y{Whun~
|'b=xeH.^<
m?>$!B4jFB
public class FileAccessI implements Serializable{ ES<"YF
bY&s$Ry3"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #*1\h=bzmW
RandomAccessFile oSavedFile; i{ eDV
long nPos; dGTAZ(1W
7[ *,t
0:Ak4L6k
public FileAccessI() throws IOException fLxFF
{ 7-Fh!=\f/
this("",0); iVREkZ2SC
} N:Q}Lil
00n6v;X
bxK1v7
public FileAccessI(String sName,long nPos) throws IOException `4gm'C
{ }`\+_@w
oSavedFile = new RandomAccessFile(sName,"rw"); ;HgV(d#X
this.nPos = nPos; owJPEx
oSavedFile.seek(nPos); }I9\=jT
} O5LB&s
ie=tM'fb
iw12x:
public synchronized int write(byte[] b,int nStart,int nLen) 7P.C~,+D%P
{ YSs9BF:a
int n = -1; $:t;WXc.<
try{ Nq"/:3@4
oSavedFile.write(b,nStart,nLen); X-e)w
n = nLen; W{?7Pn?1`
} *R0Ae 4
catch(IOException e) OtrO"K
{ {xMY2I++
e.printStackTrace (); 1wi{lJaz
} W,}HQ
=;i@,{ ~
CT6a
return n; l{E+j%
} 5kofO
oost}%WxN
ZS4lb=)G
} { P&l`
LTm2B_+
AN\:
/* '&xv)tno
**SiteInfoBean.java K\`L>B. 1
*/ mflH&Bx9
package NetFox; x$cs_q]J
^$4d'
4M}u_}9
public class SiteInfoBean { HUfH/x3zj]
bYYyXM
3;u*_ ]N_
private String sSiteURL; //Site's URL k"LbB#Q
private String sFilePath; //Saved File's Path w q% 4'(
private String sFileName; //Saved File's Name >u4%s7v
private int nSplitter; //Count of Splited Downloading File CVyqr_n65/
+>@<'YI<
EX~ U(JB6
public SiteInfoBean() +3(1QgYM%
{//nSplitter的缺省值为5 KE]!7+8-
//default value of nSplitter is 5 AVyqtztQ
this("","","",5); k ?X
} tq8B)<(]
2a3hm8%U
SYOND>E
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ik=~`3Zp0
{ S ])Ap'E
sSiteURL= sURL; D ?1$I0=
sFilePath = sPath; xVao3+r
sFileName = sName; L6fc_Mo.EE
this.nSplitter = nSpiltter; b?hdWQSW7
7q<I7Wt
P%]li`56-c
} !NUsfd
Rf+ogLa=
]2T=%(*
public String getSSiteURL() @V Bv}Jo
{ ]!E|5=q
return sSiteURL; ^z-e"
} R+ lwOVX
"6Hka{
==F[5]?
public void setSSiteURL(String value) R%Gh4y\nF
{ h3$.` >l
sSiteURL = value; U N1HBW;
} : |#Iw
)@DH&
p6$ QTx
public String getSFilePath() z_~5c
{ RMMx6L|-:
return sFilePath; {'4h.PB+r
} J@54B
,3Y~ #{,i
u.YPb@
public void setSFilePath(String value) g4cmYg3
{ *z!!zRh3x
sFilePath = value; m646|G5
} J*Dj`@`4`g
-9Wx;u4]o
@%q0fj8b
public String getSFileName() lR\=] ]7I>
{ HaXlc8
return sFileName; >:!TfuU^R
} rj&
6TvlK*<r=
~'2)E/IeV
public void setSFileName(String value) DBYD>UA
{ 9JV(}v5[
sFileName = value; rlqn39
} ^} P|L
2s_shY<=}L
dVmI.A'nbp
public int getNSplitter() PsU.dv[
{ 4h\MSTF*
return nSplitter; QijEb
} $m]~d6
n*(Vf'k
cVv+,l4V0
public void setNSplitter(int nCount) RbKAB8
{ Mt(wy%{zK
nSplitter = nCount; #80DM
} ?sWPx!tU
} r+-KrO'
xWWfts1t
-K hXb
/* h~)oiT2v
**Utility.java B- =*"H?q
*/ xwhH_[
package NetFox; 2qLRcA=R
SV}q8z\
/~)vma1<
public class Utility { rs2G{a
+e+hIMur
-e_IDE
public Utility() _IBIx\F
{ i,=greA]"
xa#0y
^=D=fX"8%
} L\|p8jJ
gq~>S1
//线程睡眠 Sr Z\]
public static void sleep(int nSecond) iK8aj)%Q@
{ o_ka'|
try{ `VX]vumG
Thread.sleep(nSecond); >MZWm6M8
} VRurn>y0
catch(Exception e) L\_MZ*<0[
{ R`q*a_
e.printStackTrace (); 0i/l2&x*k]
} ??0C"8:[
} vY0C(jK
Cg<:C?>!p
//日志 Rs,\{#
public static void log(String sMsg) 25]Mi2_
{ (dn(:<_$
System.err.println(sMsg); dmI,+hHtL
} ;S5*n:d
h^h,4H\r
o?@,f/"5
public static void log(int sMsg) ~?4'{Hc'
{ l&2A]5C
System.err.println(sMsg); 5RCQ<1
} d%VG@./xq
} T8+A`z=tSb
. #`lW7
%SuEfCM
/* :fz&)e9
**TestMethod.java awLN>KI]</
*/ aTF~rAne<
package NetFox; t<s:ut)Q!
sN0S~}F+
N)|mA)S)
public class TestMethod { L1ZhH3}X
yo]!Zn
W<C \g~\
public TestMethod() pi7Fd\A
{ ///xx/weblogic60b2_win.exe (]7&][
try{ +>mbBu!7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #s'9Ydd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ka? |_(
SiteFileFetch fileFetch = new SiteFileFetch(bean); vHSX3\(
fileFetch.start(); fWiefv[&
} C9>tj=yEY
catch(Exception e){e.printStackTrace ();} Sn=|Q4ZN
AB<|iJC
?Iy$'am]L
} _ #]uk&5a
^*(*tS|M
V)#se"GV
public static void main(String[] args) lj0"2@z3"E
{ VL=.JwK
new TestMethod(); ;1PnbU b
} }9yAYZ0q{b
} !wy Qk
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