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)); .<`i!Ls
} ig<Eyr
for(int i=0;i<nEndPos.length-1;i++) [zl@7X1{_
{ _8P"/( `Rw
nEndPos = nStartPos[i+1]; JQ=i{9iJ
} _x&;Fa%
nEndPos[nEndPos.length-1] = nFileLength; <f.*=/]W2
} %KHO}gad1
} 8@]*X,umc
W^npzgDCo
n|2`y?
//启动子线程 Z>gxECi
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `bT!_Ru
for(int i=0;i<nStartPos.length;i++) Wt4ROj
{ Gdmh#pv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T6m#sVq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C~4_Vc*
nStartPos,nEndPos,i); JBfDz0P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mR@|]T
fileSplitterFetch.start(); vw5f.8T;w
} Z:DEET!c'k
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RO[Ko-m|/N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J ^gtSn^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", HM57b>6
nEndPos = " + nFileLength); O4RNt,?l
// fileSplitterFetch[nPos.length-1].start(); ~\kJir
s7.2EkGl=
kP~'C'5Ys
//等待子线程结束 %Xs3Lz
//int count = 0; wmKM:`&[5
//是否结束while循环 @ODwO;_R5
boolean breakWhile = false; E .^5N~.
f2Zi.?``H
28FC@&'H
while(!bStop) cKuU#&FaV
{ kR$>G2$!
write_nPos(); !+T\}1f7d
Utility.sleep(500); OLh`R]Sd
breakWhile = true; |$"2R3
nX4R
S$J}>a#Ry
for(int i=0;i<nStartPos.length;i++) Xou1X$$z
{ [p[nK=&r
if(!fileSplitterFetch.bDownOver) j(^ot001%v
{ (Cjnf a 2
breakWhile = false; ^7MhnA
break; n@n608
} AzAD76iNv
} \$:KfN>WY
if(breakWhile) Fx,08
break; ~f=~tN)hZ
jJFWPD]u
hoY.2 B_
//count++; ah<1&UG,
//if(count>4) o&uO]
// siteStop(); I@Zd<Rn
} <X[TjP
h/~:}Bof
r>73IpJI
System.err.println("文件下载结束！"); #p&&w1
} h'VN& T,
catch(Exception e){e.printStackTrace ();} ?_mcg8A@@*
} (ii6w d<*
x,$N!X
J-*&&
//获得文件长度 W}m-5L
public long getFileSize() #vrxhMo
{ qu]ch&"?U
int nFileLength = -1; b`"E(S/
try{ Ci%u =%(
URL url = new URL(siteInfoBean.getSSiteURL()); o?nlnoe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M|!^ #!a(
httpConnection.setRequestProperty("User-Agent","NetFox"); kk]f*[Zi5
gXr"],OM;
@3`:aWda
int responseCode=httpConnection.getResponseCode(); ~RcI+jR)
if(responseCode>=400) 5/x"!Jk
{ Rs+rlJq
processErrorCode(responseCode); d"3S[_U
return -2; //-2 represent access is error tHNvb\MR$
} 50!/%
w-2&6o<n-
QZy+`
String sHeader; |GuIp8~
RmS|X"zc
Z(Da?6#1
for(int i=1;;i++) x._IP,vRx^
{ sYV7t*l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); []HMUL]"
//Utility.log(in.readLine()); 5.gM]si
sHeader=httpConnection.getHeaderFieldKey(i); (<sZ8n=AD
if(sHeader!=null) l;i,V;@t
{ !0ly1T 9
if(sHeader.equals("Content-Length")) Y.I-hl1<r
{ zJ{?'kp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6o@}k9AN
break; 89@\AjI
} &gJKJ=7
} ,#3}TDC
else kp3(/`xP
break; y*2R#jTA
} /dTy%hZC}
} `5 py6,
catch(IOException e){e.printStackTrace ();} (]7*Kq
catch(Exception e){e.printStackTrace ();} 3wXmX
>Gbj1>C}
n^|;J*rD
Utility.log(nFileLength); lB!`,>"c
vW4~\]
-r/G)Rs
return nFileLength; <>aBmJs4
} 5 e:Urv77
)6|7L)Dk
`(A6uakd
//保存下载信息（文件指针位置） /CpUq;^
private void write_nPos() 3/IQ]8g"
{ $ tf;\R
try{ W-wy<<~f
output = new DataOutputStream(new FileOutputStream(tmpFile)); g*b 4N_
output.writeInt(nStartPos.length); 9tZ)#@\
for(int i=0;i<nStartPos.length;i++) 9xWC<i
{ KDwz!:ye
// output.writeLong(nPos); htc& !m
output.writeLong(fileSplitterFetch.nStartPos); $q*kD#;mh
output.writeLong(fileSplitterFetch.nEndPos); -1Y9-nn[m
} gyH'92ck
output.close(); pT]M]/y/:
} &pwSd
catch(IOException e){e.printStackTrace ();} #!p=P<4M
catch(Exception e){e.printStackTrace ();} 6cof Zc$
} >}QRMn|@H
w?CbATQ
y e!Bfz>
//读取保存的下载信息（文件指针位置） EM/NT/
private void read_nPos() f@l6]z{.L
{ ~ZU;0#
try{ C("PCD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uY0V!W
int nCount = input.readInt(); CG'NC\x5
nStartPos = new long[nCount]; R`=3lY;
nEndPos = new long[nCount]; 3nuf3)
for(int i=0;i<nStartPos.length;i++) 5zJkPki
{ ) Kfk\
nStartPos = input.readLong(); <B6@q4Q
nEndPos = input.readLong(); ${'gyD
} D^Dm, -
input.close(); <'A>7M~h?*
} C%d 4ItB >
catch(IOException e){e.printStackTrace ();} g+/%r91hZ
catch(Exception e){e.printStackTrace ();} !- f>*|@
} lJ]r%YlF
!f_GR Pj'
P# 2&?.d\
private void processErrorCode(int nErrorCode) zi:F/TlUC
{ bb;fV
System.err.println("Error Code : " + nErrorCode); mY-Z$8r
} KtJE
ZWMX!>o<
WrbDB-uM
//停止文件下载 O$x-&pW`g
public void siteStop() 8o8FL~&]
{ m^zx&
bStop = true; +C7 1".i-
for(int i=0;i<nStartPos.length;i++) 7=XQgbY/
fileSplitterFetch.splitterStop(); l|`FW
XuJwZN!(
J#*Uf>5NY
} lEi,duS)
} oTtmn, T
//负责部分文件的抓取 vl$! To9R"
**FileSplitterFetch.java Wm:3_C +j
*/ Pb?H cg
package NetFox; mm$D1=h{|
>`*iM
7ka^y k@Q
import java.io.*; OXDlwbwL
import java.net.*; ))c;DJc
lp[3z&u
ub6\m=Y7
public class FileSplitterFetch extends Thread { ($(6]?J(?7
T(+F6d=1
V5rnI\:7
String sURL; //File URL ^7q=E@[e
long nStartPos; //File Snippet Start Position !mBsDn(J
long nEndPos; //File Snippet End Position X[k-J\
int nThreadID; //Thread's ID A(_AOoA'
boolean bDownOver = false; //Downing is over B%6bk.
boolean bStop = false; //Stop identical L5T)_iQ5
FileAccessI fileAccessI = null; //File Access interface HY#7Ctn3
:{4G=UbAI
6bnAVTL5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ..FUg"sSO
{ IZ')1
this.sURL = sURL; "b%hAdR
this.nStartPos = nStart; 2a.NWJS
this.nEndPos = nEnd; pALB[;9g
nThreadID = id; )xQxc.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0vG}c5;F
} {+c/$4<
)$q<"t\#P#
1E$Z]5C9
public void run() ==x3|^0y
{ q^sMJ
while(nStartPos < nEndPos && !bStop) `Q26Dk
{ N(Y9FD;H
{%D "0*^
jbIWdHZ/US
try{ Z.6`O1OY}?
URL url = new URL(sURL); wdBytH6r.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?3SlvKI}H`
httpConnection.setRequestProperty("User-Agent","NetFox"); $ajw]2kx
String sProperty = "bytes="+nStartPos+"-"; B0p>'O2
httpConnection.setRequestProperty("RANGE",sProperty); SUD]Wl7G`r
Utility.log(sProperty); =)M8>>l
-Kg@Sj/U}R
'lC"wP&$
InputStream input = httpConnection.getInputStream(); '5ky<
//logResponseHead(httpConnection); XyS#6D
u4VQx,,
]&/jvA=\l,
byte[] b = new byte[1024]; ibzYY"D:
int nRead; SNvK8,"g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O#O~A|
{ p<*-B
nStartPos += fileAccessI.write(b,0,nRead); b]RCe^E1
//if(nThreadID == 1) ^\N2 Iu>6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p5F[( H|9
} ^%_B'X9
8YkP57Y%[Z
74gU4T
Utility.log("Thread " + nThreadID + " is over!"); H'gPGOd
bDownOver = true; (i*1M
//nPos = fileAccessI.write (b,0,nRead); ?[!.TU?4N
} )2S0OY.
catch(Exception e){e.printStackTrace ();} ""pJO 6bI
} $L</{bXW
} 6/4OFvL1
"vLqYc4$
nOQ+oqM<
//打印回应的头信息 mf}?z21vD
public void logResponseHead(HttpURLConnection con) 3tXtt@Yy
{ yWzvE:!)
for(int i=1;;i++) 83R"!w18
{ @Jvw"=
String header=con.getHeaderFieldKey(i); q<c).4
if(header!=null) [&NF0c[i
//responseHeaders.put(header,httpConnection.getHeaderField(header)); R$6Y\ *L[
Utility.log(header+" : "+con.getHeaderField(header)); yE"hgdL
else )W57n)]
break; U^pe/11)H
} 8w2+t>?
} K:'pK1zy
Q]6nW[@j'
AZl=w`;/O%
public void splitterStop() 44%::Oh
{ ;uoH+`pf
bStop = true; Tr@`ozp8
} ev8E.ehD
c"O\fX
$%1[<}<
} PI?-gc?[
h)y"?Jj
h@W}xT
/* ;7m>40W
**FileAccess.java ;U20g:K
*//文件访问(定位，写) W{-N,?z
package NetFox; ny=CtU!z
import java.io.*; PI{sO |
Wb4sfP_
kN}.[enI~
public class FileAccessI implements Serializable{ *f4KmiQ~%
(9cIU2e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (b{ {B$O
RandomAccessFile oSavedFile; pM#:OlqC
long nPos; e9%6+9Y
5n9F\T5
1/&j'B
public FileAccessI() throws IOException Kjf#uU.7
{ `E|IMUB~
this("",0); ?L'k2J
} Y^6=_^
8"<!8Img
Mb<KZ_wYOX
public FileAccessI(String sName,long nPos) throws IOException =} vG|
{ Aga7X@fV(
oSavedFile = new RandomAccessFile(sName,"rw"); ;l`8w3fDt
this.nPos = nPos; mR0@R;,p
oSavedFile.seek(nPos); -Z;:_"&9
} o<g (%ncr
o&CvjE
@C!q S7k)
public synchronized int write(byte[] b,int nStart,int nLen) |2oB3 \)/
{ *uv\V@0
int n = -1; /S;?M\
try{ >yWJk9hf
oSavedFile.write(b,nStart,nLen); EAq >v t83
n = nLen; |QzPY8B9O
} Cu?$!|V
catch(IOException e) F_21`Hj
{ #15q`w
e.printStackTrace (); sV*Q8b*
} Tl1?5
}YSH8d
)8k6GO8|
return n; *Zc-&Dk:Ir
} a%]p*X!
3{c&%F~!
,J~1~fg89
} A%2!Hr
au7BqV!uL
I3L1|!
/* 7dakj>JM
**SiteInfoBean.java <B fwR$
*/ \UC4ai2MK
package NetFox; O^<6`ku
awawq9)Y
#2MwmIeA
public class SiteInfoBean { F-R`'{ ka
:#LB}=HQ
'0=U+Egp
private String sSiteURL; //Site's URL Mfz5:'
private String sFilePath; //Saved File's Path t #AQD]h
private String sFileName; //Saved File's Name eGE%c1H9a
private int nSplitter; //Count of Splited Downloading File 8t^"1ND
|z4/4Y@
lfKknp#B/O
public SiteInfoBean() tb i;X=5
{//nSplitter的缺省值为5 ~\/ J&
//default value of nSplitter is 5 >YW>=5_
this("","","",5); _x \Ll?,
} ;klDt|%3j
}+B7C2_\
55I>v3 w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j NY8)w_
{ she`_'?5
sSiteURL= sURL; [0}471
sFilePath = sPath; 0g+@WK6y
sFileName = sName; OBZ|W**N"
this.nSplitter = nSpiltter; V?"^Ff3m!
d!d 3r W;A
a_ P[J8j
} %pt$S~j
S ~_%
08f~vw"
public String getSSiteURL() bXW)n<y
{ cC[n~OV
return sSiteURL; TM}F9!*je
} 7mjj%
bDkE*4SRX
bXfOZFzq)
public void setSSiteURL(String value) WY,t> 1c
{ z>{KeX:
sSiteURL = value; 98]t"ny [
} EzyIsp> _
PYUY bRn
KCFwO'
public String getSFilePath() <7rK
{ q!TbM"
return sFilePath; g-^m\>B
} vraU&ze\1
>(CoXSV5
JXAyF6 $
public void setSFilePath(String value) e^GW[lT
{ 'k67$H
sFilePath = value; ^;3rdBprm
} ^zJ.W
&V3oW1*W
}ELCnN
public String getSFileName() =Q}mJs
{ >>cd3)b
return sFileName; Bg h$P
} &-:yn&f7
l{U3;
@,&m`qzd+
public void setSFileName(String value) cQ41NX@I
{ WS/+Yl
sFileName = value; %`1vIr(7
} }tZAU\z
ss{=::#
I 6YT|R
public int getNSplitter() "V0:Lq
{ zjS:;!8em
return nSplitter; $0SZlq>En
} 1$VI\}
b=UMoWS
Pu*HZW3l
public void setNSplitter(int nCount) ls\E%d
{ 6a7iLQA
nSplitter = nCount; {l&2Kd*
} %QgAilj,
} 2P_^@g
$F7gH
~&lJT
/* Mgs|*u-5
**Utility.java V8$bPVps
*/ u2BW]T]
package NetFox; t/WnDR/fM
zlztF$Bo
7B\(r~f`t
public class Utility { ]3,.g)U*m
r_,m\'~s!
\y`3LhY
public Utility() YIQ]]q8R!L
{ -xu.=n@,
R(83E B~_
nvK7*-
} ~:<@`
!b->u_
//线程睡眠 7 eQoc2X2
public static void sleep(int nSecond) v6-~fcX0G
{ 'xZPIj+
try{ Hq\E06S@
Thread.sleep(nSecond); M|#5gKXd
} *-AAQ
catch(Exception e) ~1r*/@M[V
{ [F)/mN
e.printStackTrace (); `vxrC&,As
} ,e FQ}&^A
} N%rL=zE
8H#c4%by)
//日志 Owpg]p yVD
public static void log(String sMsg) ,PMb9O\B
{ B/D\gjb
System.err.println(sMsg); ,V]A63J
} RvSq KW8
sMS9!{A
Wj j2J8B
public static void log(int sMsg) sp Q4m
{ z2Y_L8u2
System.err.println(sMsg); W+f&%En
} @ZkAul0@
} B+e_Y\Bu
tkN3BQ
,J(5@8(>a
/* T$^>Fiz{Se
**TestMethod.java $#7J\=GZ+
*/ 4%fN\f
package NetFox; y{`(|,[
@>Ghfh>~D
&:;;u\
public class TestMethod { f;Bfh3
.eabtGO,
Q_kT}6#(J=
public TestMethod() Z0ncN])
{ ///xx/weblogic60b2_win.exe S $_Y/x
try{ ~0F9x9V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N+s?ZE*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FQ^<,
SiteFileFetch fileFetch = new SiteFileFetch(bean); Cl9SPz
fileFetch.start(); RZ|HwYG
} g{v5mly
catch(Exception e){e.printStackTrace ();} fATA%eA8;
H6ky)kF&
HZDaV&)@
} c BHL,
,%?; \?b%h
WS1&3mOd
public static void main(String[] args) prlyaq;4
{ G/fP(o-Wd
new TestMethod(); c+8>EU AW
} tt7PEEf
} gVa+.x]
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