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)); D!oZ?dGCo6
} ]/Vh{d|I&
for(int i=0;i<nEndPos.length-1;i++) )s7bJjT0=X
{ V1<ow'^i
nEndPos = nStartPos[i+1]; aD2*.ln><
} tM)Iir*U#
nEndPos[nEndPos.length-1] = nFileLength; QU.0Elw
} 7i8eg*Gl
} *C\(wL
z!$gVWG
gmY/STN
//启动子线程 a:A n=NA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +0J@y1
for(int i=0;i<nStartPos.length;i++) |xh&p(
{ Z==!C=SBv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GM](=|F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )u;JwFstX
nStartPos,nEndPos,i); .d~\Ysve
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )GVBE%!WEd
fileSplitterFetch.start(); uFZ~
} ~Rs#|JWB2V
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), il12T`a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z`Ax pTl
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'WQdr(
nEndPos = " + nFileLength); <FUon
// fileSplitterFetch[nPos.length-1].start(); D*\v0=P'?
R:~(Z?
?q_^Rj$
//等待子线程结束 zG#wu
//int count = 0; Q&xjF@I
//是否结束while循环 `FZF2.N
boolean breakWhile = false; %zzYleJ!]
;WD,x:>blO
f^p^Y F+
while(!bStop) GW3>&j_!d
{ xYI;V7
write_nPos(); .n`( X#,*l
Utility.sleep(500); ~.Cv DJy
breakWhile = true; @RGDhwS47
CbOCk:,g5
Stxp3\jEn
for(int i=0;i<nStartPos.length;i++) q\Rq!7(
{ SWs3SYJ\
if(!fileSplitterFetch.bDownOver) T~Ly^|Ihz
{ CvK3H\.&;k
breakWhile = false; qbiK^gR
break; X4wH/q^
} ZQAO"huk]
} ,[isib3
if(breakWhile) 6YmP[%
break; ;F5"}x
R)oB!$k
%<}<'V0
//count++; fW(/Loh
//if(count>4) @vRwzc\
// siteStop(); ]78!!G[`
} pYo=oI
W;zpt|kAH
XA<ozq'
System.err.println("文件下载结束！"); XJgh>^R^
} 7+nm31,<O
catch(Exception e){e.printStackTrace ();} >{5 p0
} \\:|Odd
1u~ MXGF
"3fBY\>a
//获得文件长度 =gjDCx$|
public long getFileSize() sI,W%I':d
{ [A5W+pDm
int nFileLength = -1; _?`&JF?*
try{ gKo%(6{n~
URL url = new URL(siteInfoBean.getSSiteURL()); a460|w6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c8ZA5|
httpConnection.setRequestProperty("User-Agent","NetFox"); Qz,|mo+
w^q7n
gEwd &J
int responseCode=httpConnection.getResponseCode(); *geN[[
if(responseCode>=400) >&U@f
{ ST Z]8cw
processErrorCode(responseCode); m#e*c[*G
return -2; //-2 represent access is error V`#.7uUP
} C\}/"
lpgd#vr
y('k`>C
String sHeader; RWKH%C[Yd
FhkkWWL
3mO;JXd
for(int i=1;;i++) m$wlflt
{ ]~0}=,H$N
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5~'IKcW<
//Utility.log(in.readLine()); jlqv2V7=/
sHeader=httpConnection.getHeaderFieldKey(i); /,s[#J
if(sHeader!=null) }Fa%%}
{ J?&l*_m;t
if(sHeader.equals("Content-Length")) V'G Ju
{ CMW,slC_3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,.tfWN%t\
break; 9Uf j
} +f|BiW
} a.2L*>p
else ;H'gT+t<c
break; ;_O)p,p
} (JUZCP/\
} `P}9i@C
catch(IOException e){e.printStackTrace ();} $}GTG'*.
catch(Exception e){e.printStackTrace ();} F;q#&
Kibr ]w
Hfym30
Utility.log(nFileLength); N&,]^>^u
fv!?Ga(
-/P\"c
return nFileLength; .}B(&*9,v
} X4|4QgY
x=q;O+7]
~" i0x
//保存下载信息（文件指针位置） 1}%B%*N
private void write_nPos() T{+Z(L
{ B<?wh0
try{ c>:R3^\lwx
output = new DataOutputStream(new FileOutputStream(tmpFile)); RY9V~8|M
output.writeInt(nStartPos.length); c{3wk7
for(int i=0;i<nStartPos.length;i++) E"~2./+rd
{ /Ncm^b4
// output.writeLong(nPos); 9X$ma/P[
output.writeLong(fileSplitterFetch.nStartPos); a<~77~"4wn
output.writeLong(fileSplitterFetch.nEndPos); eHiy,IN
} 47K1$3P
output.close(); tDg}Ys=4K>
} )2IH 5
catch(IOException e){e.printStackTrace ();} [ic870_
catch(Exception e){e.printStackTrace ();} O@V%Cu
} r!PpUwod
^T::-pN*
iBTYY{-wF
//读取保存的下载信息（文件指针位置） S!v(+|
private void read_nPos() <{5EdX
{ _Q[$CcDEE
try{ qOih`dla
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ar9]"s+'
int nCount = input.readInt(); ;r[@v347
nStartPos = new long[nCount]; HlvuW(,x=
nEndPos = new long[nCount]; RTh`ENCKR
for(int i=0;i<nStartPos.length;i++) <r#eL39I
{ Vw||!d
nStartPos = input.readLong(); m,UGWR
nEndPos = input.readLong(); :a ->0 l
} pi<TFe@eG
input.close(); anMF-x4/*q
} R_XR4)(<
catch(IOException e){e.printStackTrace ();} ?W^c4NtP
catch(Exception e){e.printStackTrace ();} UcOk3{(z$q
} R\@/U=iqR
/1mW|O>0
,I1RV
private void processErrorCode(int nErrorCode) 0j"8@<
{ }X*Riu7gk
System.err.println("Error Code : " + nErrorCode); li~d?>
} ia\eLzj
8_<4-<}P:
9l,a^@Y:
//停止文件下载 ?=m?jNa;nC
public void siteStop() tg]x0#@s
{ ~T&<CTh
bStop = true; &0 >Loja`^
for(int i=0;i<nStartPos.length;i++) s7Ub@
fileSplitterFetch.splitterStop(); ?qCK7$j
pn.wud}R
MjlP+; !
} $YN6<5R)
} ),G=s Oo
//负责部分文件的抓取 #wL
**FileSplitterFetch.java 'EDda
*/ P:30L'.=[
package NetFox; 5?hw !
%?e& WLS
N(I&
import java.io.*; %3NqSiMs
import java.net.*; <B9C*M"4%
*s9C!wYMZ
8!Vl
public class FileSplitterFetch extends Thread { BZzrRC
~HOy:1QhE=
Ecd;<$tk
String sURL; //File URL ,lZB96r0
long nStartPos; //File Snippet Start Position ,AxdCT
long nEndPos; //File Snippet End Position QUu}Xg:
int nThreadID; //Thread's ID G:~k.1y[
boolean bDownOver = false; //Downing is over nqInb:
boolean bStop = false; //Stop identical v?KC%
FileAccessI fileAccessI = null; //File Access interface \"X!2
bGc~Wr|
Vx~,Uex0+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b0lq\9
{ $2W%2rZ
this.sURL = sURL; (p2K36,9m
this.nStartPos = nStart; UK<Nj<-'t
this.nEndPos = nEnd; zIh['^3.n
nThreadID = id; T6 '`l?H`;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bbrXgQ`s+w
} c-B cA
9FB19
=EHUR'
public void run() zuUW|r
{ !o:f$6EA~C
while(nStartPos < nEndPos && !bStop) D#3\y*-y?
{ rg^'S1x|
-i0~]*
:A/d to
try{ 5H*\t 7
URL url = new URL(sURL); TWA-.>c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z'"tB/=W
httpConnection.setRequestProperty("User-Agent","NetFox"); :]\([Q+a
String sProperty = "bytes="+nStartPos+"-"; eEuvl`&
httpConnection.setRequestProperty("RANGE",sProperty); <StN%2WQ1
Utility.log(sProperty); .&DhN#EN0
+j< p \Kn>
,6-:VIHQ
InputStream input = httpConnection.getInputStream(); Wk)OkIFR
//logResponseHead(httpConnection); u6AA4(
5`~PR :dN
x[a<mk
byte[] b = new byte[1024]; vN`klDJgW[
int nRead; ibj87K
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vX/T3WV
{ A"L&a l$i
nStartPos += fileAccessI.write(b,0,nRead); gt@m?w(
//if(nThreadID == 1) -*1J f&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #qK:J;Sn3
} |y(Q
f&Gt|
}H^+A77v
Utility.log("Thread " + nThreadID + " is over!"); KV(Q;~8"X
bDownOver = true; >CHrg]9
//nPos = fileAccessI.write (b,0,nRead); lhy*h_>
} ?l9XAWt\
catch(Exception e){e.printStackTrace ();} |olA9mp|]
} nAv#?1cjz
} aDU<wxnSvO
k$blEa4
sB7# ~pA
//打印回应的头信息 Zy`m!]G]80
public void logResponseHead(HttpURLConnection con) h1de[q)
{ 16=sij%A
for(int i=1;;i++) Sc;BCl{=|
{ 4K\G16'$v
String header=con.getHeaderFieldKey(i); 8Vr%n2M
if(header!=null) AE[b},-[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A^USBv+9`
Utility.log(header+" : "+con.getHeaderField(header)); .P8&5i)'P,
else T;r2.Pupn
break; +S o4rA*9
} Ayxkv)%:@)
} uXn1 'K<'2
uvkz'R=
c2l@6<Ww
public void splitterStop() 0XE4<U
{ eA2@Nkw~)
bStop = true; %)1y AdG 8
} CsGx@\jN
>;e~WF>+K
,E S0NA
} C5o#i*|
>qnko9V
wW>A_{Y
/* M:Pc,
**FileAccess.java xF!,IKlBBp
*//文件访问(定位，写) LSL/ZvSP
package NetFox; akp-zn&je
import java.io.*; =$'6(aDH
f6hnTbJ
+$ 'Zf0U
public class FileAccessI implements Serializable{ &u$Q4
'DP1,7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 75T%g!c#
RandomAccessFile oSavedFile; (7wc*#}
long nPos; 5_GYrR2
M\uiq38
+%<(E
public FileAccessI() throws IOException W+I!q:p4H
{ /:m-> T
this("",0); @0Ic3C[rH6
} Ni9/}bb
<? q?Mn
YvaK0p0Z
public FileAccessI(String sName,long nPos) throws IOException "H'B*vc-
{ J!dm-L
oSavedFile = new RandomAccessFile(sName,"rw"); D+lAhEN
this.nPos = nPos; .s?L^Z^
oSavedFile.seek(nPos); PxvyN_B#>
} L>jY.d2w=K
]C!gQq2'a
u-QB.iQ+s
public synchronized int write(byte[] b,int nStart,int nLen) ha]VWt%}
{ f\|w'
int n = -1; n@<YI
try{ V'z1
oSavedFile.write(b,nStart,nLen); )1?y 8_B
n = nLen; f z'@_4hg
} LBw1g<&
catch(IOException e) g];!&R-
{ p_RsU`[
e.printStackTrace (); l!D}3jD
} ~[t[y~Hup
zfJT,h-{
b6,iZ+]
return n; Z@4Arfl
} `'DmDg
5AFJC?
k =>oO9`
} .YtKS
w'>pY
R$R*'l
/* !z\h|wU+
**SiteInfoBean.java \1k79c
*/ Hus)c3Ty7
package NetFox; '{cIAw/"n
E^B'4
L^1NY3=$
public class SiteInfoBean { (>LF(ll
?tWaI{95I
Yj&F;_~
private String sSiteURL; //Site's URL )v'WWwXY>
private String sFilePath; //Saved File's Path l0|5t)jF-
private String sFileName; //Saved File's Name LP.]9ut
private int nSplitter; //Count of Splited Downloading File .yoH/2h
k$n|*kCh
/J]5H
public SiteInfoBean() jk;j2YNPw
{//nSplitter的缺省值为5 1.}d.t
//default value of nSplitter is 5 A @i
this("","","",5); tm|ZBM
} z<MsKD0Q
9Gvd&U
[*Z;\5&P
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (Lbbc+1m
{ %Tfbsyf%f
sSiteURL= sURL; ))qy;Q,
sFilePath = sPath; C"y(5U)d
sFileName = sName; dn&s*
this.nSplitter = nSpiltter; #NQMy:JHD)
.j ?W>F
!Z1@}`V&;
} 0j^Kgx
B`EJb71^Xy
Lc}LGq!
public String getSSiteURL() T6'^EZZY
{ N:^n('U&j
return sSiteURL; kXViWOXU^
} EfqX y>W
N"Z{5A
&eJfGt5
public void setSSiteURL(String value) pJ>P[
{ &j;wCvE4+
sSiteURL = value; ez7A4>/
} 2_>N/Z4T
%:i7s-0w
;xy"\S]
public String getSFilePath() [|v][Hwv
{ \P[Y`LYL
return sFilePath; VMZMG$C
} sWhZby7
QL(n} {.%
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public void setSFilePath(String value) 82+r^t/.
{ !M(xG%M-V
sFilePath = value; 6W/`07'
} %O;:af"Ja8
W"scV@HKu
EAUEQk?9
public String getSFileName() YqscZ(L:y
{ `Gs9Xmc|
return sFileName; ?4YGT
} a,,exi
H8=N@l
IW5,7.
public void setSFileName(String value) e1yt9@k,
{ `>o{P/HN
sFileName = value; ,KH#NY]
} *;W+>W
I{|O "8
U4'#T%*
public int getNSplitter() 6bg ;q(*7
{ {qk1_yP
return nSplitter; sJKI!
} XPc^Tq
Lj({[H7D!
.xCZ1|+gG
public void setNSplitter(int nCount) x>K Or,f
{ 4Z3su^XR
nSplitter = nCount; 1C+13LE$U
} }J}-//[A
} 2DA]i5
`bq<$e
w7L{_aom
/* b!t0w{^w
**Utility.java kdiM5l70
*/ f_OQ./`
package NetFox; \doUTr R
G[PtkPSJ
#\{l"-
public class Utility { 38B2|x
4> K42m
=jN.1}
public Utility() b=C*W,Q_#
{ As&Sq-NWf
ZvM(Q=^
<_L,t 1H{
} qz_7%c]K[
LBeF&sb6
//线程睡眠 6q\bB
public static void sleep(int nSecond) w{8xpAqm
{ j^sg6.Z*
try{ (XTG8W sN
Thread.sleep(nSecond); k=$TGqQY?
} ;nfdGB
catch(Exception e) bW427B0
{ Wu/]MBM
e.printStackTrace (); BKCiIfkZ
} 5Pc;5 o0C
} 8Al{+gx@?
r8?gD&c}
//日志 8 /]S^'>
public static void log(String sMsg) tU5zF.%
{ KfEx"94
System.err.println(sMsg); Y1\}5k{>
} &&8x%Pml
!qQl@jO
eS^7A}*wd-
public static void log(int sMsg) )u&|_&g{}J
{ L<cx:Vz
System.err.println(sMsg); k9R4Y\8P
} NN{?z!
} yPBZc h%-
.NC!7+1m
s]0{a.Cpv
/* !PlEO 2at
**TestMethod.java Dj?> <@
*/ [85spub&}
package NetFox; ($MlXBI
@gEUm_#HTs
D/gw .XYL
public class TestMethod { .hb:s,0mP
3pROf#M
C 82omL
public TestMethod() Qy<P463A(l
{ ///xx/weblogic60b2_win.exe wU36sCo
try{ ~vhE|f
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); BwEN~2u6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _.Nbt(mz
SiteFileFetch fileFetch = new SiteFileFetch(bean); Et_bH%0
fileFetch.start(); ^Z+?h&%%
} eQm1cgMdz
catch(Exception e){e.printStackTrace ();} gs[uD5oo<
2jItq2.>
7F7{)L
} J4C.+![!Ah
W(Fv l
^)S;xb9
public static void main(String[] args) Rok7n1gW
{ UgSB>V<?
new TestMethod(); Xl{P8L
} HRCT}
} 558V_y:
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