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)); rHi4Pw{L
} `(ik2#B`}
for(int i=0;i<nEndPos.length-1;i++) T2n3g|4
{ S>)[n]f
nEndPos = nStartPos[i+1]; w IP4Z^
} t .}];IJP
nEndPos[nEndPos.length-1] = nFileLength; ~ToU._
} gm%cAme
} <k0/O
[RF]lM]w
|?]doBm|
//启动子线程 t 4VeXp6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1=,y+Xpw
for(int i=0;i<nStartPos.length;i++) 4U16'd
{ WEJ-K<A(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !iq|sXs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E*IP#:R
nStartPos,nEndPos,i); =ZO lE|4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X7[gfKGL)N
fileSplitterFetch.start(); $$uMu{?0i
} pTB7k3g
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t-5Y,}j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k]^ya?O]p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~L>86/hP,N
nEndPos = " + nFileLength); 0m=57c$O
// fileSplitterFetch[nPos.length-1].start(); 6^!fuIZ;_
cRuN;
zWv0y8[d
//等待子线程结束 yn"4qC#Z
//int count = 0; J .VZD
//是否结束while循环 O;5lF
boolean breakWhile = false; G')zDx
}'faf{W
Yg,;l-1
while(!bStop) c&x1aF "B
{ 74a@/'WbE
write_nPos(); V#5$J Xp
Utility.sleep(500); ky-nP8L}
breakWhile = true; 9e c},~(
J3(E{w8Q
4 R(m$!E!
for(int i=0;i<nStartPos.length;i++) 0\vG <
{ QxN1N^a0
if(!fileSplitterFetch.bDownOver) qE|syA9
{ &r~s3S{pQ
breakWhile = false; QQ_7Q^
break; H9PnJr8 \
} 1q@R04i
} X:I2wJDs\
if(breakWhile) jr_z ?
break; hF$qH^-c*A
<hj2'dU
~%C F3?e6
//count++; [0hahR
//if(count>4) A)V*faD
// siteStop(); 01n132k
} y4LUC;[n
:enR8MS
<9piKtb|L
System.err.println("文件下载结束！"); uo J0wG.
} f$6N
catch(Exception e){e.printStackTrace ();} 7Xu#|k
} zA8@'`Id
1DhC,)+D}q
d6ef)mw
//获得文件长度 vV*J;%MO
public long getFileSize() )XGz#C_P
{ Lt=32SvTn
int nFileLength = -1; q\x.e.@
try{ Rw%?@X3m]
URL url = new URL(siteInfoBean.getSSiteURL()); #{{p4/:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u '/)l}
httpConnection.setRequestProperty("User-Agent","NetFox"); Nh_\{ &r
aK95&Jyw&
hc+B+-,
int responseCode=httpConnection.getResponseCode(); N%xCyZ
if(responseCode>=400) ,ofE*Wt
{ -egnMc67
processErrorCode(responseCode); DyCzRkH
return -2; //-2 represent access is error e,VF;Br
} ,z>-_HOnw
86N,04
fZ5 UFq_~s
String sHeader; 83SK<V6
IQ~qiFCf
}8#Ed;%K
for(int i=1;;i++) bT&{8a
{ u~j H
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R:YVmqd
//Utility.log(in.readLine()); %),u0:go
sHeader=httpConnection.getHeaderFieldKey(i); !C05;x8{
if(sHeader!=null) 5cinI^x)f
{ MTZCI}
if(sHeader.equals("Content-Length")) }O>1tauI
{ `G/g/>y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }`Ya;
break; rU&Y/
} P1T{5u!T
} pR93T+X
else NWvIwt{
break; _<FUS'"
} h=gtuaR4
} 8K-P]]
catch(IOException e){e.printStackTrace ();} MiIxj%,(
catch(Exception e){e.printStackTrace ();} 2Kz$y JTp
vN\[2r%S
V%PQlc.X
Utility.log(nFileLength); `Ucj_6&Tqs
D@gC(&U/6
k|?[EWIi^
return nFileLength; 3&7? eO7*
} * 7Ov.v%
&C+2p
3PZ(Kn<
//保存下载信息（文件指针位置） 1h?ve,$
private void write_nPos() Yq6 @R|u
{ CYgokS\=,
try{ &Wcz~Gx3Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); Se'SDJl=
output.writeInt(nStartPos.length); &BrFcXF
for(int i=0;i<nStartPos.length;i++) /go[}X5QR[
{ 8]^|&"i.\d
// output.writeLong(nPos); Wn+s:ov
output.writeLong(fileSplitterFetch.nStartPos); #eOHe4Vt
output.writeLong(fileSplitterFetch.nEndPos); ,^8':X"A{!
} \f? K74
output.close(); `|?<KF164
} <I34@;R c
catch(IOException e){e.printStackTrace ();} [B;okW
catch(Exception e){e.printStackTrace ();} t-KicLr
} _$c o Y
r^}0qO,XM
3kC|y[.&
//读取保存的下载信息（文件指针位置） x4c|/}\)*
private void read_nPos() aYT!xdCI
{ ~LpkA`Hn!
try{ /X.zt `
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Lk,q~
int nCount = input.readInt(); SDO:Gma
nStartPos = new long[nCount]; 'LPyh ;!f
nEndPos = new long[nCount]; te-xhJ&K
for(int i=0;i<nStartPos.length;i++) (9I(e^@]
{ q9rm9#}[J#
nStartPos = input.readLong(); FsJk"$}
nEndPos = input.readLong(); jDb\4QyC
} 7WS$fUBi
input.close(); (KyOo,a
} re[5lFQ~Z
catch(IOException e){e.printStackTrace ();} NL$z4m0
catch(Exception e){e.printStackTrace ();} }k-8PG =
} XdCP!iq*8
E#:!&{O
b.RU%Y#>\
private void processErrorCode(int nErrorCode) /Tm+&Jd
{ ?[zw5fUDS
System.err.println("Error Code : " + nErrorCode); AF"7 _
} InbB2l4G
UzaAL9k
GJcxqgk$
//停止文件下载 4z(B`t~7
public void siteStop() 4bA^Gq
{ 7:?\1a
bStop = true; T^|k`
for(int i=0;i<nStartPos.length;i++) AaA!U!B
fileSplitterFetch.splitterStop(); "NLuAB.P
Hq::F?
.(q'7Q Z/
} dV38-IfGkl
} HP]5"ziA
//负责部分文件的抓取 OS@uGp=
**FileSplitterFetch.java s2SV
*/ m8{8r>6*
package NetFox; N s0,Z#Z+
,H+Y1N4W(
U[x$QG6m!
import java.io.*; F><_gIT
import java.net.*; mN]WjfII
]#f%Dku.m
ljZRz$y
public class FileSplitterFetch extends Thread { 4E5;wH
M{G}-QK_.
NJsaTBT
String sURL; //File URL U&BCd$
long nStartPos; //File Snippet Start Position _xCYh|DlQ|
long nEndPos; //File Snippet End Position aq_K,li#w
int nThreadID; //Thread's ID (@XQ]S}L
boolean bDownOver = false; //Downing is over Tph^o^
boolean bStop = false; //Stop identical ,b!D8{W"N
FileAccessI fileAccessI = null; //File Access interface V9$T=[
AE~a=e\x
i8e*9;4@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Fnak:R0
{ Ez|NQ:o
this.sURL = sURL; 3JQ7Cc>
this.nStartPos = nStart; *4%pXm;
this.nEndPos = nEnd; EOu[X'gLr
nThreadID = id; d%0Gsga}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q`r| DcN~
} 4Z%1eOR9V
/A,w{09G
3S+9LOrhY
public void run() PF/K&&9}
{ #)~u YQ
while(nStartPos < nEndPos && !bStop) D(']k?
{ bKsjbYuo
*:xOenI
8]`#ax 5
try{ |D-[M_T5
URL url = new URL(sURL); RR[zvH} E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )TiM>{
httpConnection.setRequestProperty("User-Agent","NetFox"); T}^3Re`i
String sProperty = "bytes="+nStartPos+"-"; 41Q5%2
httpConnection.setRequestProperty("RANGE",sProperty); _"@:+f,
Utility.log(sProperty); Up?RN%gq
q( ~rk
:5&D6
InputStream input = httpConnection.getInputStream(); xD&n'M]
//logResponseHead(httpConnection); ;G8H'gM07
kHhp;<
Ny7*MZ-
byte[] b = new byte[1024]; T>% 5<P
int nRead; _*e_?]G-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rc[~S
{ vc"!3x-G*
nStartPos += fileAccessI.write(b,0,nRead); @6~lZgXOV[
//if(nThreadID == 1) tIDN~[1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :2nsi4
} $T3_~7N
*V',@NH#Os
ni{'V4A
Utility.log("Thread " + nThreadID + " is over!"); H@@ 4n%MK
bDownOver = true; \B~g5}=
//nPos = fileAccessI.write (b,0,nRead); ~;CNWJtcf(
} \ZADY.ha
catch(Exception e){e.printStackTrace ();} q&z'S
} ;dUKFdKH}
} nktGO
ZAfuW^r
WlQCPC
//打印回应的头信息 %:`v.AG
public void logResponseHead(HttpURLConnection con) o]&q'>Rf
{ /jJD {
for(int i=1;;i++) *]U`]!Esp
{ `$JvWN,kB
String header=con.getHeaderFieldKey(i); /5Qh*.(S
if(header!=null) Qb?a[[3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kll!tT-N-
Utility.log(header+" : "+con.getHeaderField(header)); r craf4%
else KJQ8Yhq
break; Ll; v[Y
} RBf#5VjOG!
} FCNYfjB%
nu+K N,3R"
/xJD/"Y3&
public void splitterStop() w*XM*yJHU
{ 4Pc-A
bStop = true; wJ2cAX;"
} nE8z1hBUq
"|Q.{(|kO1
VnW6$W?g
} bdstxjJ`
hQx*#:ns
+'gO%^{l
/* BkB_?^Nv8
**FileAccess.java f> Jj5he/
*//文件访问(定位，写) Rs"=o>Qu
package NetFox; 6agG*x
import java.io.*; {rMf/RAE
36OQHv;&
?:9y !Q=
public class FileAccessI implements Serializable{ x+4K,r;
7<]&pSt=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %OgK{h
RandomAccessFile oSavedFile; i kfJ!f
long nPos; K_L7a>Fr
$7AsMlq[(
I1>f2/$z*
public FileAccessI() throws IOException Cydo~/
{ u|}\Af
this("",0); u~uz=Yse
} GYQ:G=
A@< !'
HcIJ&".~
public FileAccessI(String sName,long nPos) throws IOException #sCR}
{ ?P[:,0_
oSavedFile = new RandomAccessFile(sName,"rw"); q-Z<.GTq
this.nPos = nPos; m-uXQS^@G
oSavedFile.seek(nPos); Vc9Bg2f5
} ":+d7xR?o
</_QldL_
,H6P%
public synchronized int write(byte[] b,int nStart,int nLen) j%` C
{ @uyQH c,V
int n = -1; &q|vvF<G
try{ W[J2>`k9
oSavedFile.write(b,nStart,nLen); E va&/o?P|
n = nLen; wry`2_c
} ."dT6uE
catch(IOException e) OAq-(_H
{ l=XZBe*[g'
e.printStackTrace (); TW&s c9
} #\X)|p2
-S]ercar
k0j4P^d
return n; A nl1+
} ]*a(^*}A%
0O'M^[=d.8
b&`~%f-
} >(H:eRKq
x/{-U05
m_Hg!Lg
/* :a&M]+!
**SiteInfoBean.java 5:gpynE|
*/ 2&S^\kf
package NetFox; qfT9g>EF
b~fl,(sZp
[F*yh9%\
public class SiteInfoBean { y]{b4e
?yAb=zI1b
A*0X~6W
private String sSiteURL; //Site's URL K3:z5j.X
private String sFilePath; //Saved File's Path 4S4MQ
private String sFileName; //Saved File's Name Nk-xnTZ"
private int nSplitter; //Count of Splited Downloading File STu(I\9
R-pON4D"*
1d49&-N
public SiteInfoBean() L>/$l(
{//nSplitter的缺省值为5 zZ-/S~l
//default value of nSplitter is 5 g~21|Sa$[
this("","","",5); /xgC`]-
} qdk!.A{
c(Y~5A{TXO
m %+'St|qr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :1f,%Z$,q
{ 4IZAJqw(*
sSiteURL= sURL; E^n!h06~G
sFilePath = sPath; ~ a2A"#f
sFileName = sName; ]v:,<=S
this.nSplitter = nSpiltter; Iw[zN[oz
9-j-nx @)
DmgDhNXKq
} lv]U)p
$Xo_8SX,
k2->Z);X
public String getSSiteURL() uYs45 G
{ ,DHH5sDCn
return sSiteURL; Q3+%8zZI
} zhow\l2t}
bh8GP]*E|
]GRVU
public void setSSiteURL(String value) @)Vb?|3
{ .&]3wB~
sSiteURL = value; 2va[= >_
} 4Kj8i
qYe`</
L=#B>Eu
public String getSFilePath() s'tXb=!HO
{ \``w>Xy8
return sFilePath; F',1R"/}
} z I9jxwXU
NlhC7
fMf;
public void setSFilePath(String value) D3g5#.$,}>
{ +-t&li%F
sFilePath = value; (oiQ5s^f
} '#A_KHD
ok,O/|E}?
0*P-/)o x
public String getSFileName() gmTBp}3
{ ,^ -%<
return sFileName; \s8h.xjU
} pT+OPOSR
,%/F,O+#
e 0$m<5
public void setSFileName(String value) hUi5~;Q5Fi
{ H]V(qq{
sFileName = value; hb1h.F
} [Ti' X#
8$JJI({bH
@CR<&^s5V
public int getNSplitter() #l)o<Z
{ wk'(g_DP
return nSplitter; 3:sc%IDP
} 1A;,"8kBd
A Ef@o+A
]_s;olKNI
public void setNSplitter(int nCount) HIj:?y
{ o|84yT!~
nSplitter = nCount; Qe7 SH{
} o^uh3,.
} Ia9!ucN7DA
?o]NV
B2BG*xa
/* kSge4?&
**Utility.java !eb{#9S*
*/ \l[AD-CZPh
package NetFox; N-}OmcO]e
XkW@"pf&Fh
@/01MBs;
public class Utility { b<r*EY
[r]<~$
pR*3Q@Ng
public Utility() C2iOF/4
{ m=pH G
RAEN &M
&QHmo*
} {9@E[bWp#
DB jUHirK
//线程睡眠 Q[`2?j?
public static void sleep(int nSecond) .Xxxz Wyk
{ `N7erM
try{ &8%^o9sH
Thread.sleep(nSecond); Iw$T'I+4W
} z __#PQ,n
catch(Exception e) Uq%|v
{ "$"<AKCwS
e.printStackTrace (); rTC|8e
} ~Wm'~y>
} g*9&3ov
8z&/{:Z@pH
//日志 f4X}F|!h
public static void log(String sMsg) '/ueY#eG
{ +~ S7]AZ
System.err.println(sMsg); |CS&H2!s
} >Zf*u;/dW$
su-0G?c
q{yzux
public static void log(int sMsg) >X>]QMfh
{ z;0]T=g
System.err.println(sMsg); [ifQLsHA
} OWN|W,
} %z @T /
A}"uEk(R
oY@]&A^ah
/* m1p%,
**TestMethod.java el^<M,7!
*/ K^I$05idi
package NetFox; )gR3S%Ju
dt>!=<|k
Z%-uyT@a
public class TestMethod { .L]2g$W\p
brn>FFAwO
@:9mTP7
public TestMethod() gr>FLf
{ ///xx/weblogic60b2_win.exe Xn<|6u
try{ D{t0OvQag
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h!hv{c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PO2]x:
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5'0kf7
fileFetch.start(); >R/^[([;]
} r^\Wo7q
catch(Exception e){e.printStackTrace ();} 0wETv
D>wo>,G
.B$3y#TOb
} Ujly\ix`
%N<>3c<8P
C|ou7g4'p
public static void main(String[] args) %ZlnGr
{ y2C/DyuAY|
new TestMethod(); \g@jc OKU
} L\<J|87p?
} %cMayCaI!@
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