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)); &gvX<X4e
} V4%7Xj
for(int i=0;i<nEndPos.length-1;i++) 4-xg+*()
{ Cz4l
nEndPos = nStartPos[i+1]; M""X_~&I"
} OgyHX>}bH
nEndPos[nEndPos.length-1] = nFileLength; D_I_=0qNd
} 8GT{vW9
} jATN):8W
4+0:(=>[%
B|BJkY'
//启动子线程 & =vi]z:[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z#olKBs
for(int i=0;i<nStartPos.length;i++) DTx>^<Tk
{ M5LqZyY
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 55x.Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k%cT38V*
nStartPos,nEndPos,i); u O~MT7~[X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Uw>g^[V;
fileSplitterFetch.start(); E`3[62C
} Z9PG7h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [i N}W5 m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _5768G`P
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `"E<%$|ZQy
nEndPos = " + nFileLength); xTdh/}
// fileSplitterFetch[nPos.length-1].start(); cU=EXyP%
HBgt!D0MZ
MqswYK-s
//等待子线程结束 |Iq\ZX%q
//int count = 0; .n| M5X
//是否结束while循环 Y3f2RdGl
boolean breakWhile = false; =)XC"kUp
fTA%HsvU:
<F5x}i~(C
while(!bStop) p4wXsOQ}
{ 5A"OL6ty
write_nPos(); Aj2yAg
Utility.sleep(500); ]4oF!S%F
breakWhile = true; l,M?
+Tp>3Jh2
EWoGdH|
for(int i=0;i<nStartPos.length;i++) KZTT2KsYl
{ SNf*2~uq)
if(!fileSplitterFetch.bDownOver) x-s]3'!L
{ Y-:{a1/RKo
breakWhile = false; ucC'SS
break; A!!W\Jt
} p\/;^c`7
} k7Xa|&fQP<
if(breakWhile) e?!A]2
break; "zBYhZr
FDO$(&
/*{s1Zcb
//count++; |<1
//if(count>4) WJ$!W
// siteStop(); v`pIovn
} H!dg(d^
q:ZF6o`Z83
m]:|j[!*M
System.err.println("文件下载结束！"); $[8GFv
} @phb5
catch(Exception e){e.printStackTrace ();} BDT1qiC
} N[AX]gOJ
Q>emyij
ibskce{H
//获得文件长度 6N'v`p8
public long getFileSize() N!:&Xz
{ &7t3D?K'qX
int nFileLength = -1; ]l4#KI@
try{ P_ x9:3
URL url = new URL(siteInfoBean.getSSiteURL()); ey>V^Fj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r5N.Qt8
httpConnection.setRequestProperty("User-Agent","NetFox"); zHvG3Ed@
hbv>Jjd
Kr'5iFK7
int responseCode=httpConnection.getResponseCode(); $&iw(BIq
if(responseCode>=400) %B'*eBj~fw
{ -5t.1/
processErrorCode(responseCode); ht%:e?@i
return -2; //-2 represent access is error %JC-%TRWK
} %$L!N-U6
zQQ=8#]
p$ %D
String sHeader; IH1 fvW e
H$i4OQ2
'm,3znX!c
for(int i=1;;i++) 9My |G)M6
{ nv^nq]4'Dq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yb:Xjg7
//Utility.log(in.readLine()); { 'Db
sHeader=httpConnection.getHeaderFieldKey(i); <Sx-Ca7
if(sHeader!=null) &}G2;O}3
{ )a%kAUNj
if(sHeader.equals("Content-Length")) xr*hmp1
{ VUaYK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }&OgIo+
break; k-&fPEjG
} h}o7/p
} +5:oW~ ;
else yY$:zc"J
break; co$I htOv
} E/</
} IMDGinHAy
catch(IOException e){e.printStackTrace ();} b-rgiR$cg
catch(Exception e){e.printStackTrace ();} as?~N/}
Z;bg;@r|
q'%-8t
Utility.log(nFileLength); <k0$3&D
se1\<YHDS
fH/J8<
return nFileLength; >Hq)1o
} " E U[Lb
8f37o/L
|lOH PA
//保存下载信息（文件指针位置） q;p:)Q"
private void write_nPos() VnB"0"%w
{ b]Xc5Dp{
try{ ,dM}B-
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,Mp/Y>f
output.writeInt(nStartPos.length); &nk[gb o\
for(int i=0;i<nStartPos.length;i++) I8C(z1(N
{ 9fyJw1
// output.writeLong(nPos); ,s*-2Sz
output.writeLong(fileSplitterFetch.nStartPos); WZa?Xb
output.writeLong(fileSplitterFetch.nEndPos); &cEQ6('H
} wua`e <"
output.close(); INFbj8T
} t`6R)'
catch(IOException e){e.printStackTrace ();} V]V~q ]
catch(Exception e){e.printStackTrace ();} a.r+>44M
} ~hSr06IY
ep-~;?
I'M,p<B
//读取保存的下载信息（文件指针位置） G:HPd.ay
private void read_nPos() ;-:Nw6 E
{ 8R;)WlLu=
try{ :qbbo~U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vnT'.cBB:^
int nCount = input.readInt(); >:s#MwIwm
nStartPos = new long[nCount]; [4u.*oL&
nEndPos = new long[nCount]; -Q6njt&
for(int i=0;i<nStartPos.length;i++) ]\y:AkxhJ
{ b'Scoa7@'
nStartPos = input.readLong(); tp-PE?
nEndPos = input.readLong(); ~9Nn8g6
} s3sAw~++
input.close(); u/5^N^@^
} Ps@a@d"83
catch(IOException e){e.printStackTrace ();} [/B$cH
catch(Exception e){e.printStackTrace ();} df=G}M(
} }i7Gv K<[:
y my/`%
z3V[ Vi
private void processErrorCode(int nErrorCode) "w#jC~J<W
{ #Ont1>T,G
System.err.println("Error Code : " + nErrorCode); bnb:4?d]
} %z}{jqD&:X
ai!zb2j!E
~|_s2T
//停止文件下载 |2#)lGA
public void siteStop() qHT_,\l2
{ U,?[x2LF
bStop = true; cN}Aeo
for(int i=0;i<nStartPos.length;i++) @j/UDM
fileSplitterFetch.splitterStop(); :`~;~gW<
k?%?EsR
Bg"KNg
} bG`aF*10)!
} dWhki|c
//负责部分文件的抓取 9"5J-a'
**FileSplitterFetch.java {s8v0~
*/ E>t5/^c)*w
package NetFox; HAof,* h$
\>b :
8J}gj7^8
import java.io.*; osS?SuQTE
import java.net.*; JVPl\I
r &<sSE;5
W+v7OSd92
public class FileSplitterFetch extends Thread { 9A@/5Z:v5W
8U98`# i
jA&ZO>4
String sURL; //File URL 3oH.1M/
long nStartPos; //File Snippet Start Position T}%8Vlt]
long nEndPos; //File Snippet End Position U}w,$ Y
int nThreadID; //Thread's ID +K6j p
boolean bDownOver = false; //Downing is over k}xXja*
boolean bStop = false; //Stop identical 5%+M:B
FileAccessI fileAccessI = null; //File Access interface MN wMF
sp=;i8Y 3
8.9Z0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tVB9kxtE
{ C,2k W`[V
this.sURL = sURL; 0+\%os V
this.nStartPos = nStart; zGDLF`
this.nEndPos = nEnd; ws!pp\F
nThreadID = id; ak:Y<}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 : MfY8P)
} O] T'\6w
4CUzp.S`h
kj$Ks2!W
public void run() ,4O|{Iu#n
{ k[{h$
while(nStartPos < nEndPos && !bStop) h!k[]bt5
{ tZW2TUM]
- '<K_e;
I?2S{]!?
try{ G?p !*7N
URL url = new URL(sURL); p_^Jr*Mv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =;hz,+
httpConnection.setRequestProperty("User-Agent","NetFox"); it Byw1/
String sProperty = "bytes="+nStartPos+"-"; (n4\$LdP-
httpConnection.setRequestProperty("RANGE",sProperty); ULqFJ*nla
Utility.log(sProperty); Oz3JMZe
~F gxhK2+
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InputStream input = httpConnection.getInputStream(); k}MmgaT:5]
//logResponseHead(httpConnection); _>b=f
<'{*6f@n
6ol*$Q"z
byte[] b = new byte[1024]; _#9F@SCA
int nRead; 41Y1M]`=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v:$Ka@v6
{ qK_jgj=w
nStartPos += fileAccessI.write(b,0,nRead); zWN<"[agc
//if(nThreadID == 1) }:04bIaV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v- 793pr
} z(00"ei
mE|?0mRA %
zla^j,
Utility.log("Thread " + nThreadID + " is over!"); %QYH]DR
bDownOver = true; n(#|
//nPos = fileAccessI.write (b,0,nRead); aR- ?t14
} ';>]7oT`
catch(Exception e){e.printStackTrace ();} h83W;s
} <$"
} *H2@lrc
9oe=*#Ig1m
No|T#=BZ[
//打印回应的头信息 wFe?0u
public void logResponseHead(HttpURLConnection con) @%aU)YDwi
{ Q%_QT0H9Kz
for(int i=1;;i++) ^x BQ#p
{ #N?VbDK9_
String header=con.getHeaderFieldKey(i); W 'w{}|
if(header!=null) ^k*h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kYW>o}J|
Utility.log(header+" : "+con.getHeaderField(header)); *n"{]tj^>
else zwLJ|>
break; q(Q$lRj/I-
} ?RP&XrD
} UrMEL;@g
]!um}8!}
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public void splitterStop() |~+i=y
{ O`M6=\
bStop = true; [3@Pu.-I+M
} D1ep7ykY
43'!<[?x
5YZh e4R
} _A>?@3La9
MWl2;qi
)z".lw
/* m@,u&9K
**FileAccess.java ;4MC/Q/
*//文件访问(定位，写) V_x8 Q+~?
package NetFox; {^z>uRZ3
import java.io.*; |E}-j;(
prk@uYCa =
^t2b`n60
public class FileAccessI implements Serializable{ 6E)emFkQ
TJO?BX_9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 GJ9'i-\*\
RandomAccessFile oSavedFile; iAl.(j
long nPos; j;7:aM"BQW
*^+]`S
j5Cf\*B4J
public FileAccessI() throws IOException hFQ*50n}
{ ]B2%\}c
this("",0); k#oe:u`<
} ,pTj'I
)8Q;u8jm1
qexnsL
public FileAccessI(String sName,long nPos) throws IOException _{ Np_(g
{ J4woZ{d
oSavedFile = new RandomAccessFile(sName,"rw"); +~7x+6E
this.nPos = nPos; .7<6 zG6J
oSavedFile.seek(nPos); ?niv}/'%O
} ns&3Dh(IVP
)` ^/Dj;
S^q%+Z
public synchronized int write(byte[] b,int nStart,int nLen) .rcXxV@f
{ 59l9^<{A
int n = -1; Clo}kdkd_
try{ H#+2l?D:"
oSavedFile.write(b,nStart,nLen); EK%J%NY
n = nLen; ~_]i'ii8
} r,r"?}Z
catch(IOException e) ty>9i]Y-
{ u[<ij
e.printStackTrace (); GzN /0:b
} sqv!,@*q
hU~up a<dD
^&z3zFTp
return n; N0V`xrS
} g9.y`o}c
W[G5+*i
DUMC4+i
} W}iDT?Qi
ul&}'jBr
\gW6E^
/* KlGmO;k
**SiteInfoBean.java 84g8$~M
*/ .5E6MF
package NetFox; +v)+ k
?Z2_y-
cl{kCSZo.z
public class SiteInfoBean { IQ $/|b/
Htm;N2$d
qCI0[U@
private String sSiteURL; //Site's URL 1]wo
private String sFilePath; //Saved File's Path (RBB0CE
private String sFileName; //Saved File's Name wlEmy.)H
private int nSplitter; //Count of Splited Downloading File 2~y<l
+'"NKZ.>TT
= tY%k!R
public SiteInfoBean() 89YG `
{//nSplitter的缺省值为5 sHPK8Wsg
//default value of nSplitter is 5 9TUB3x^
this("","","",5); ,ieew`
} ai]KH7
cR6Rb[9 N
qir8RPW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y;VmA#k`
{ !E~czC\p6
sSiteURL= sURL; QR\2%}9b
sFilePath = sPath; S#F%OIx
sFileName = sName; WxJV zHtR
this.nSplitter = nSpiltter; El^V[s'3
+ZJ1> n
>*1YL)DBT\
} p1']+4r%
N+zR7`AG8
``,q[|
public String getSSiteURL() mNPz%B
{ Z5Tu*u=
return sSiteURL; !a7YM4D
} _ YcIGOL
0/JTbf. CX
\y0]BH
public void setSSiteURL(String value) G7YBo4v
{ 4CK$W`V
sSiteURL = value; A,;[9J2\&
} `OHdo$Y9
)5ev4Qf
2&0#'Tb
public String getSFilePath() +wE>h>?;
{ =kBWY9:$,
return sFilePath; ZJ%iiY
} 3a?dNwM@
.|/VD'xV"
=GL^tAUJ
public void setSFilePath(String value) 1$nuh@-ys
{ iHk/#a
sFilePath = value; =p \eh?^
} 6Zmzo,{
F @uOXNz)
NI2-*G_M
public String getSFileName() M!O &\2Q
{ }UWi[UgA
return sFileName; `C)|}qcC
} Og:aflS
3z!^UA>q
Gf<%bQE
public void setSFileName(String value) P] Xl
{ o>y@1%aU
sFileName = value; LYMb)=u]
} I6Oc`S!L
w^)_Fk3
qFwAzW;"
public int getNSplitter() !4}Wp.
{ HEs.pET\
return nSplitter; #OsUF,NU
} xeKfc}:&z
g)=-%n'RoE
POb2U1Sj
public void setNSplitter(int nCount) 8C5*:x9l
{ zxy/V^mu
nSplitter = nCount; hEfFMi=a`
} f"d4HZD^
} L r9z~T:ED
:pGgxO%q
?#J;[y\^
/* D)J'xG_<O
**Utility.java f=Kt[|%'e
*/ ~?:Xi_3Lo
package NetFox; mO@Sl(9
VRvX^w0
vve[.Lud'
public class Utility { f= 33+8I
JA "
%P`|kPW1
public Utility() l/6(V:
{ M*<Bp
1*]@1DJt
0T<DHPQ1
} sXR}#*8p
{p7b\=WB-
//线程睡眠 nm !H&#<
public static void sleep(int nSecond) 3.D|xE]g
{ OIrr'uNH
try{ l~$Od jf
Thread.sleep(nSecond); NqZR*/BOz
} oU)HxV
catch(Exception e) ^ZG 3{>
{ g?e-D.pSF
e.printStackTrace (); Q) Y&h'.(
} <j^"=UN4#
} c7/fQc)h4d
'DCB 7T8
//日志 [p 8fg!|
public static void log(String sMsg) d>jRw
{ T`r\yl}
System.err.println(sMsg); ZsL-vlv
} Q=.j>aM+_
R\>=}7
?ubIh.d
public static void log(int sMsg) tzSg`7H!
{ ?KXgG'!!
System.err.println(sMsg); Iw;J7[hJ&$
} Avo"jN*<d
} M{M?#Q
nuLxOd*n
5: O,-b&
/* Tp fC
**TestMethod.java }Oh@`xTxt
*/ TF;}NQ
package NetFox; P] 9-+
w@\quy:
\:d|'r8OCM
public class TestMethod { h2fTG
bx%P-r31
.LEn~ 8
public TestMethod() {-kV~p
{ ///xx/weblogic60b2_win.exe o0Pc^
try{ +}@6V4BRn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); So\f[/em
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x $=-lB
SiteFileFetch fileFetch = new SiteFileFetch(bean); ZHW|P
fileFetch.start(); *q+z5G;O
} pxO?:B
catch(Exception e){e.printStackTrace ();} sXm,y$\m
DeL7sU
E/N*n!sV
} z\Y-8a.]
/Jw65 e
<-m?l6
public static void main(String[] args) uZ7~E._
{ 0G"I}Jp{
new TestMethod(); L?p,Sy<RI
} d!]fou
} V;t8v\
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