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)); -7J|l
} ^7zu<lX
for(int i=0;i<nEndPos.length-1;i++) 1I@8A>2^OX
{ N7E$G{TT
nEndPos = nStartPos[i+1]; _@S`5;4x
} |@NiW\O
nEndPos[nEndPos.length-1] = nFileLength; T91moRv
} @36u8pE
} z[`@}}Q
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,h"-
//启动子线程 T\~x.aH`^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bR@p<;G|
for(int i=0;i<nStartPos.length;i++) =X.LA%Sf=u
{ Z{&cuo.@<]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [Nn`l,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }neY<{z
nStartPos,nEndPos,i); c'/l,k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |5Xq0nvCe
fileSplitterFetch.start(); U9b?i$
} ~4"qV_M
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y0eE-5F,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4pw6bK,s2\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L(&&26Y
nEndPos = " + nFileLength); quY:pqG38q
// fileSplitterFetch[nPos.length-1].start(); ca+5=+X7
%p%%~ewmx
q, O$ %-70
//等待子线程结束 H"A7Zo
//int count = 0; %|s+jeUDn|
//是否结束while循环 n:MdYA5,m
boolean breakWhile = false; 6@DF
J!5$,%v
J:V?EE,\-
while(!bStop) *_>Lmm.yh
{ d!eYqM7-G
write_nPos(); "DYJ21Ut4
Utility.sleep(500); U&O: _>~
breakWhile = true; N-lkYL-%\j
vVOh3{e|
'],J$ge
for(int i=0;i<nStartPos.length;i++) @S|XGf
{ 1GzAG;UUo6
if(!fileSplitterFetch.bDownOver) y5!KXAQ%
{ a+n0|CvF
breakWhile = false; T=ev[ mS
break; x7O-Y~[2
} JtER_(.
} |\pbir
if(breakWhile) #U14-^7
break; 3Z1CWzq(
O({2ivX
`V##Y
//count++; .V,@k7U,V
//if(count>4) FSND>\>
// siteStop(); p,#o<W
} ob8qe,_'
4:FK;~wM&x
V:y'Qf2M
System.err.println("文件下载结束！"); F w?[lS
} `nu''B H
catch(Exception e){e.printStackTrace ();} Ofs<EQ
} $< JaLS
9 AJ(&qY(
4r45i:
//获得文件长度 A}l3cP; `#
public long getFileSize() dkz=CY3p%X
{ q.;u?,|E/
int nFileLength = -1; s7F.sg
try{ 4t=G
URL url = new URL(siteInfoBean.getSSiteURL()); PUUwv_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wRVUu)
httpConnection.setRequestProperty("User-Agent","NetFox"); uA<n
ez|)ph7
]9^sa-8
int responseCode=httpConnection.getResponseCode(); ~sh`r{0
if(responseCode>=400) ?32&]iM oW
{ w(L4A0K[
processErrorCode(responseCode); E 7{U|\
return -2; //-2 represent access is error H*}y^)x
} ~A\GT$
1eF3`
LcTP#
String sHeader; )P sY($ &
Bx< <~[Ws}
lNYt`xp
for(int i=1;;i++) @u6B;)'l
{ a!v1M2>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ZpQ)IHA.
//Utility.log(in.readLine()); cPlZXf
sHeader=httpConnection.getHeaderFieldKey(i); ]Gsv0Xk1
if(sHeader!=null) s*.hl.k.
{ T{-CkHf9Q
if(sHeader.equals("Content-Length")) ~UP[A'9jJ
{ Jcd-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J| w>a
break; VZKvaxIk6
} Wi)_H$KII
} 9dx/hFA
else |Y,b?*UF
break; <eWf<
} ZbdZrE$
} X aMJDa|M
catch(IOException e){e.printStackTrace ();} ,?^ p(w
catch(Exception e){e.printStackTrace ();} ,s"^kFl
N2;B-UF 7
f6&iy$@
Utility.log(nFileLength); 0Qf,@^zL*
P/W XaE4
[M=7M}f;
return nFileLength; "ut39si
} z7fp#>uw
I 7{T
#Lh;CSS
//保存下载信息（文件指针位置） *nkoPVpC
private void write_nPos() R{SF(g3
{ inMA:x}cF1
try{ _Tm3<o.
output = new DataOutputStream(new FileOutputStream(tmpFile)); 'a@/vx&J
output.writeInt(nStartPos.length); KW pVw!
for(int i=0;i<nStartPos.length;i++) <h0?tv]
{ rlOAo`hd
// output.writeLong(nPos); t-tg-<
output.writeLong(fileSplitterFetch.nStartPos); ia!y!_L\'
output.writeLong(fileSplitterFetch.nEndPos); g}1B;zGf
} V17%=bCZ5[
output.close(); iP ->S\
} r@H /kD
catch(IOException e){e.printStackTrace ();} "#2a8#
catch(Exception e){e.printStackTrace ();} nFHUy9q
} "R;U/+
@@Kp67Iv
8V`WO6*
//读取保存的下载信息（文件指针位置） 6d<r= C=
private void read_nPos() &5B'nk"
{ vXrx{5gz
try{ YYBDRR"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (c=6yV@
int nCount = input.readInt(); ];[}:f
nStartPos = new long[nCount]; Nk? ^1n$
nEndPos = new long[nCount]; dy%;W%
for(int i=0;i<nStartPos.length;i++) ; F"g$_D0
{ *&^Pj%DX
nStartPos = input.readLong(); B"1c
nEndPos = input.readLong(); yg<R=$n,Q
} rr],DGg+B]
input.close(); /~%&vpF-L
} U]H#MiC!
catch(IOException e){e.printStackTrace ();} ) j#`r/
catch(Exception e){e.printStackTrace ();} FpmM63$VN[
} 2*;~S44
H)kwQRfu
9<6;Hr,>G
private void processErrorCode(int nErrorCode) |6sp/38#p
{ q376m-+
System.err.println("Error Code : " + nErrorCode); 823Y\x~>
} Q4#m\KK;i9
_{YWXRC#
/K@XzwM
//停止文件下载 ;PF<y9M
public void siteStop() {4<C_52t
{ N2^=E1|_
bStop = true; c<B/V0]
for(int i=0;i<nStartPos.length;i++) MzdV2.
fileSplitterFetch.splitterStop(); & p
/|6N*>l)y
/$Nsd
} /=nJRC3.
} }c,}V
//负责部分文件的抓取 24 'J
**FileSplitterFetch.java z% ?+AM)P
*/ @e.C"@G
package NetFox; X:"i4i[}{9
Cn34b_Sbd
|.: q
import java.io.*; RB7tmJc
import java.net.*; ^,TO#%$iE
]nn98y+
!Iy_UfW
public class FileSplitterFetch extends Thread { i &nSh ]KK
]g3JZF-
@alK;\
String sURL; //File URL zZPO&akB"
long nStartPos; //File Snippet Start Position _}Ac n$
long nEndPos; //File Snippet End Position =7=]{Cx[
int nThreadID; //Thread's ID oq Xg
boolean bDownOver = false; //Downing is over Ju@c~Xm
boolean bStop = false; //Stop identical EHJ.T~X
FileAccessI fileAccessI = null; //File Access interface g*AWE,%=|
*aM=Z+
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Xx~Bp+
{ jp%S3)
this.sURL = sURL; `KoV_2|
this.nStartPos = nStart; ~^:A{/
this.nEndPos = nEnd; T4Uev*A
nThreadID = id; <44G]eb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hD 82tr
} lfow1WRF
*w`sM%]Rq
vH@ds k
public void run() 2*& ^v
{ pI\]6U
while(nStartPos < nEndPos && !bStop) UcHJR"M~c
{ R B
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-$ls(oot
try{ rpha!h>w1%
URL url = new URL(sURL); q"lSZ; 'E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -=Q*Ml#I
httpConnection.setRequestProperty("User-Agent","NetFox"); ~!d\^Z^i
String sProperty = "bytes="+nStartPos+"-"; 9s q
httpConnection.setRequestProperty("RANGE",sProperty); dFB]~QEK
Utility.log(sProperty); GR_-9}jQP
(mpNcOY<D
lukB8
InputStream input = httpConnection.getInputStream(); CY5Z{qiX
//logResponseHead(httpConnection); A}9`S6@@
xJ]\+ 50
}o(-=lF
byte[] b = new byte[1024]; Q(?#'<.#
int nRead; kVMg 1I@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &U#|uc!+
{ B~ GbF*j
nStartPos += fileAccessI.write(b,0,nRead); .*Y
//if(nThreadID == 1) 5|s\*bV`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 013x8!i
} #=A)XlZMd
e X|m
AQvudx)@"
Utility.log("Thread " + nThreadID + " is over!"); 6A-|[(NS
bDownOver = true; 904}Jh,
//nPos = fileAccessI.write (b,0,nRead); G5 WVr$
} O<?R)NH-P
catch(Exception e){e.printStackTrace ();} 14yv$,
} ^6V[=!& H
} "ze|W\Bv!
&j"?\f?
g}cq K
//打印回应的头信息 yR{3!{r3(
public void logResponseHead(HttpURLConnection con) #q=Efn'
{ +a+Om73B2
for(int i=1;;i++) ^hM4j{|&M
{ *.t7G
String header=con.getHeaderFieldKey(i); Zb>?8
if(header!=null) <\^8fn
//responseHeaders.put(header,httpConnection.getHeaderField(header)); f2`2,?
Utility.log(header+" : "+con.getHeaderField(header)); VY4yS*y
else sDlO#
break; aEeodA<(
} Z@!+v19^
} e*NnVys
/nA{#HY
YNF k
public void splitterStop() BW4J>{
{ htF] W|z
bStop = true; T(Eugl"
} NZ0;5xGR
"+G8d'%YV
2^nxoye
} !Wnb|=j
0M[EEw3
'5$b-x6F
/* >|UOz&
**FileAccess.java j A%u 5V
*//文件访问(定位，写) /*mI<[xb
package NetFox; ^<2p~h0 \
import java.io.*; 8&slu{M- t
/a4{?? #e
4|DWOQ':
public class FileAccessI implements Serializable{ (O3nL.
2P0*NQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 F={a;Dvrn
RandomAccessFile oSavedFile; UP,c|
long nPos; 83#mB:^R
}o`76rDN
(f"4,b^]
public FileAccessI() throws IOException _q-*7hCQ`
{ `b$.%S8uj=
this("",0); !+v$)3u9
} o>pJPV
SwMc pNo
oCz/HQoBk
public FileAccessI(String sName,long nPos) throws IOException vEJbA
{ 9\7en%(M
oSavedFile = new RandomAccessFile(sName,"rw"); cbTm'}R(G
this.nPos = nPos; i9x+A/o[
oSavedFile.seek(nPos); /j.9$H'y
} ;:NJCuG
Q\Vgl(;lX
gg2(5FPP
public synchronized int write(byte[] b,int nStart,int nLen) w\O;!1iU
{ 4o[{>gW
int n = -1; sfl<qD+?
try{ \'O"~W
oSavedFile.write(b,nStart,nLen); )Pv%#P-<
n = nLen; o`-msz
} 6Z"X}L,*
catch(IOException e) }N52$L0[
{ Z *x'+X
e.printStackTrace (); j0q&&9/Jj
} CpTjJXb
3u0RKLc\
r9?Mw06Wc5
return n; dSHDWu&
} TB31- ()
^U/O!GK
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} `Urhy#LC
FGzwhgy
0w7DsPdS
/* ;!Fn1|)
**SiteInfoBean.java q!@4~plz
*/ pd$[8Rmj_
package NetFox; _lq`a\7e
Tw<q,O
6_B]MN!(
public class SiteInfoBean { ,PDQzJY
MF'JeM;H
6ik$B
private String sSiteURL; //Site's URL o)/ 0a
private String sFilePath; //Saved File's Path "#g}ve,
private String sFileName; //Saved File's Name iWR)ke
private int nSplitter; //Count of Splited Downloading File <F'\lA9
J<lW<:!3]
JW&gJASGC
public SiteInfoBean() gjlx~.0d
{//nSplitter的缺省值为5 !5!<C,U
//default value of nSplitter is 5 {{!-Gr
this("","","",5); Q+{n-? :
} %(Icz?
*0ro0Z|Iq
r.U`Kh]K
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^<6[.)
{ gRzxLf`K
sSiteURL= sURL; VIbq:U
sFilePath = sPath; E{vbO/|kf
sFileName = sName; N2o7%gJw
this.nSplitter = nSpiltter; *m(=V1"
4skD(au8
%a7$QF]
} e|r`/:M
~}Pfu
B#R|*g:x
public String getSSiteURL() EdX$(scu~B
{ NHE18_v5
return sSiteURL; !VzC&>'v^9
} ~$J2g
o+VQ\1as?(
B)UZ`?>c
public void setSSiteURL(String value) w32y3~
{ 9- #R)4_
sSiteURL = value; fN2lLn9/u
} y1#1Ne_
-:rUw$3J
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public String getSFilePath() 8FhdN
{ iURe([@
return sFilePath; B-mowmJ3dg
} 5lum$5
|':{lH6+1
Y4YJJYvD
public void setSFilePath(String value) T> p&$]OG
{ ;FEqe49
sFilePath = value; pK4)yu+
} 1.>m@Slr>
ptaKf4P^r
lLIAw$
public String getSFileName() @}ZVtrz
{ 6dYMwMH
return sFileName; "Y.y:Vv;
} V.2_i*
e}W)LPR!
phz&zlD
public void setSFileName(String value) FGkVqZ Y2?
{ |l!aB(NW
sFileName = value; 7[wPn`v2
} dF2RH)Ud
D/' dTrR
Qg/rRiV
public int getNSplitter() ss-D(K"
{ e:W{OIz:
return nSplitter; 6MI8zRX
} 8b=_Y;
5LMw?P.<
LH6vLuf
public void setNSplitter(int nCount) }PpUAt~g
{ _ x*3PE
nSplitter = nCount; >R=|Wo`Ri
} wKHBAW[i]
} #A.@i+Zv
54qFfN8O
fc@A0Hf
/* 13wE"-
**Utility.java 048kPXm`
*/ DV{=n C
package NetFox; Hx:;@_gq
hv+zGID7
$od7;%
public class Utility { %XTI-B/K
x)VJFuqy
=\d?'dII:
public Utility() Xm&L BX
{ \`"ht
']oQ]Yx0
w*Ihk)
} {>;R?TG]$
L0]_X#s>#
//线程睡眠 92-I~ !d
public static void sleep(int nSecond) WPDyu.QD
{ O H7FkR
try{ =w^M{W.w
Thread.sleep(nSecond); S[QrS7
} E)3NxmM#
catch(Exception e) C*lJrFpB
{ 9>$p
e.printStackTrace (); -Qe Z#w|
} A\;U3Zu
} .sA.C]f
'ig'cRD6N
//日志 :H[6Lg\*
public static void log(String sMsg) z$Qbj
{ 0(btA~'*
System.err.println(sMsg); SY8C4vb'h
} U<-D(J
CH/rp4NeSy
^W@5TkkBQq
public static void log(int sMsg) "h ^Z
{ )CyS#j#=
System.err.println(sMsg); 2BobH_H
} J-4:H gx
} 'W#D(l9nI
1nOCQ\$l
bN88ua}k{
/* |Ds=)S" K
**TestMethod.java A(N4N
*/ \di=
package NetFox; RGX=)
c"xK`%e
UZ$/Ni
public class TestMethod { E!AE4B1bd
c:g'.'/*
8i,K~Bu=
public TestMethod() kNL\m[W8$
{ ///xx/weblogic60b2_win.exe 0?M:6zf_iv
try{ [8*)8jP3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _tXlF;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .[ mRM
SiteFileFetch fileFetch = new SiteFileFetch(bean); *9i{,I@
fileFetch.start(); KGpA2Nx
} ]:\dPw`A
catch(Exception e){e.printStackTrace ();} .x1NWGDn
KYN0
E~:x(5'%d
} jA/w|\d!
D,ln)["xm
Q3SS/eNP
public static void main(String[] args) Y4(
{ K4);HJ|=
new TestMethod(); m#F`] {
} ],v=]+R
} o8vug$=Z
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