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)); nu,#y"WQ
} qO=_i d
for(int i=0;i<nEndPos.length-1;i++) #5GIO
{ (: IUg
nEndPos = nStartPos[i+1]; >_QC_UX>4i
} VOBzB]
nEndPos[nEndPos.length-1] = nFileLength; u7>b}+ak&
} -f0Nb+AR
} !dB {E
:8}QKp
*Dld?Q
//启动子线程 ` bd
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <8MKjf
for(int i=0;i<nStartPos.length;i++) `r+"2.z*
{ 27*u^N*z@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jw$3cwddH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4C^;lK
nStartPos,nEndPos,i); P"0S94o:5J
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V,bfD3S3
fileSplitterFetch.start(); THirh6
} b:.aZ7+4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A87JPX#R?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'v^CA}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c[]_gUp8
nEndPos = " + nFileLength); bs!N~,6h
// fileSplitterFetch[nPos.length-1].start(); 5uMh#dm^
v_f8zk
I*R[8|
//等待子线程结束 _aVrQ@9
//int count = 0; F)/}Q[o8
//是否结束while循环 JqTkNKi/s
boolean breakWhile = false; _^Lv8a3(O
][-N<
[-!
while(!bStop) I_@\O!<y}
{ }}XYV eI
write_nPos(); cZKK\hf<
Utility.sleep(500); )W)m?%
breakWhile = true; UKp- *YukT
{]plT~{e
{dJC3/Rf
for(int i=0;i<nStartPos.length;i++) !b0'd'xe
{ 7''l\3mIn
if(!fileSplitterFetch.bDownOver) pv&:N,p
{ 3o%,8l,
breakWhile = false; @cdd~9w
break; %3scz)4$
} naCPSsei
} 2bxkZS]
if(breakWhile) 24"Trg\WK[
break; O[f*!
Q=J"#EFs
f7 V36Q8
//count++; 8;;!2>N
//if(count>4) uZ( I|N$
// siteStop(); H];|<G
} R*IO%9O
A_1cM#4
mh]'/C_*<w
System.err.println("文件下载结束！"); ?-0k3
} %)T>Wn%b]v
catch(Exception e){e.printStackTrace ();} ;4tVFqR
} +[*VU2f t
%o9@[o .]
`E>HpRcxD
//获得文件长度 aO('X3?
public long getFileSize() ZB GLwe
{ C J S
int nFileLength = -1; )ALPMmlRs
try{ pkpD1c^
URL url = new URL(siteInfoBean.getSSiteURL()); IRNL(9H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |WH'aGG
httpConnection.setRequestProperty("User-Agent","NetFox"); b'Qia'a%
"P HkbU
q%TWtQS
int responseCode=httpConnection.getResponseCode(); &Yi)|TU3'R
if(responseCode>=400) [hA%VF.9
{ "l!WO`.zp=
processErrorCode(responseCode); M3@Wb@
return -2; //-2 represent access is error Hrq1{3~
} ^]w!ow41
y:(OZ%g
IY6DZP
String sHeader; 24PEt%2
c^vPd]Ed
\"B?'Ep;
for(int i=1;;i++) 'HTr02riY
{ sHD8#t^{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); py.lGywb_
//Utility.log(in.readLine()); /%9D$\
sHeader=httpConnection.getHeaderFieldKey(i); $E3-</ f
if(sHeader!=null) e*p7(b-
{ zWpJ\/k~
if(sHeader.equals("Content-Length")) r2}u\U4>
{ =; Gw=m(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %0C<_drW
break; u-PAi5&n
} GZ0? C2\
} C( 8i0(1
else W[BZ/
break; t!QuM_i3
} jY%&G#4
} 6nh!g
catch(IOException e){e.printStackTrace ();} ;q]Jm
catch(Exception e){e.printStackTrace ();} dfY(5Wc+f
GL$!JKWp
0X@!i3eu
Utility.log(nFileLength); hc OT+L>
>Jh*S`e
DhY.5
return nFileLength; d4KTwn5g
} I Y%M5(&Q
n2&*5m&$
W1'F)5(?7
//保存下载信息（文件指针位置） uKc x$
private void write_nPos() IvGQ7 VLr
{ eqbQ,, &
try{ 0+MNu8t
output = new DataOutputStream(new FileOutputStream(tmpFile)); \MBbZB9@
output.writeInt(nStartPos.length); 2g5i3C.q$
for(int i=0;i<nStartPos.length;i++) HA&7 ybl
{ $U%M]_
// output.writeLong(nPos); Z-|.j^n
output.writeLong(fileSplitterFetch.nStartPos); 0JzH dz
output.writeLong(fileSplitterFetch.nEndPos); Oxs O
} }a?PBo`
output.close(); 85CH% I#
} ~_opU(;f
catch(IOException e){e.printStackTrace ();} aX`"V/
catch(Exception e){e.printStackTrace ();} TI4#A E
} ,5oe8\uz
CXt9 5O?
%@tKcQ
//读取保存的下载信息（文件指针位置） (5- w>(
private void read_nPos() 68Po`_/s
{ nZZNx
try{ JPQWRK^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); su;u_rc,
int nCount = input.readInt(); G165grGFd
nStartPos = new long[nCount]; 2%|
nEndPos = new long[nCount]; X[/>{rK
for(int i=0;i<nStartPos.length;i++) 0VsQ$4'V^
{ ?>c*[>LpZ
nStartPos = input.readLong(); 6. N?=R
nEndPos = input.readLong(); "fK`F/
} *69{#qN
input.close(); -e<d//>
} e RY2.!
catch(IOException e){e.printStackTrace ();} Fp'qn'){:#
catch(Exception e){e.printStackTrace ();} ^X-3YhJ4U
} ,/0Q($oz
rR`'l=,t
zVN/|[KP4
private void processErrorCode(int nErrorCode) GL;@heP
{ 3ARvSz@5
System.err.println("Error Code : " + nErrorCode); Gk_%WY*
} ,=sbK?&
pde,@0(Fa
\7b-w81M-
//停止文件下载 DUH\/<^g
public void siteStop() {UqSq
{ wM.z/r\p
bStop = true; X&C&DTB
for(int i=0;i<nStartPos.length;i++) j("$qpv
fileSplitterFetch.splitterStop(); \H(r }D$u<
_vOV(#q2a
\H<gKZquR
} >,c$e' h
} 8VG6~>ux'>
//负责部分文件的抓取 ^n8ioL\*i
**FileSplitterFetch.java +m?;,JGt
*/ &\<!{Y<'
package NetFox; MJ5Ymt a
N>h/!# ZC
d4ANh+}X"_
import java.io.*; ,TeJx+z^
import java.net.*; LX<arHz
V~#e%&73FH
3OnIAk3
public class FileSplitterFetch extends Thread { <JtH/oN
Bmx+QO
Mdk(FG(
String sURL; //File URL ]vj.s/F~
long nStartPos; //File Snippet Start Position L1J \C
long nEndPos; //File Snippet End Position /V'^$enK!}
int nThreadID; //Thread's ID U@t"o3E
boolean bDownOver = false; //Downing is over $DPMi9,7^
boolean bStop = false; //Stop identical 8yW8F26
FileAccessI fileAccessI = null; //File Access interface wyzx9`5~d
/<[S> ;!kr
&6]+a4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException '?| (QU:)F
{ feJzX*u
this.sURL = sURL; 9Z?P/ o
this.nStartPos = nStart; 7D'-^#S5
this.nEndPos = nEnd; /#mq*kNIM6
nThreadID = id; .II*wKk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b1+6I_u.
} H~Z$pk%
` =ocr8c
v[$-)vs*ag
public void run() C]@v60I
{ Zl,c+/
while(nStartPos < nEndPos && !bStop) }"} z7Xb0
{ 'Cki"4%<
'u9,L FO
$~>3bik@
try{ a[e&O&Z
URL url = new URL(sURL); hz:^3F`>/&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $'Pn(eZHGv
httpConnection.setRequestProperty("User-Agent","NetFox"); q%H`/~AYM
String sProperty = "bytes="+nStartPos+"-"; G.j R
httpConnection.setRequestProperty("RANGE",sProperty); S8=Am7D]1
Utility.log(sProperty); g/*x;d=
m(2(Caz{
"n<rP 3y
InputStream input = httpConnection.getInputStream(); 7JC^+rk
//logResponseHead(httpConnection); c}XuzgSY
)q.Z}_,)@
^O>G?a
byte[] b = new byte[1024]; ZD$W>'m{F
int nRead; K&L9Ue
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) NxOiT#YH
{ euxkw]`h6
nStartPos += fileAccessI.write(b,0,nRead); J#k3iE}
//if(nThreadID == 1) '(ZJsw
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Mn)>G36(
} Oup5LH!sW
iJ8 5okv'
8PN/*Sa
Utility.log("Thread " + nThreadID + " is over!"); .`I;qF
bDownOver = true; \o|5/N
//nPos = fileAccessI.write (b,0,nRead); 0wFa7PyG?
} L&D+0p^lI
catch(Exception e){e.printStackTrace ();} =1!,A
} \VL_
} wEQ7=Gyx
M<Gr~RKmAn
V)pn)no'V
//打印回应的头信息 i|`b2msvd
public void logResponseHead(HttpURLConnection con) Sf_q;Ws
{ _'eG
for(int i=1;;i++) |)%]MK$;
{ [{s 1=c
String header=con.getHeaderFieldKey(i); 4[\$3t.L
if(header!=null) / 7i>0J]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JPo.&5k
Utility.log(header+" : "+con.getHeaderField(header)); 33R1<dRk
else D)kh"cK*1
break; UJ\[^/t
} {z^6V\O5
} WA'&0i4
S\\3?[!p
W^o*^v
public void splitterStop() trl:\m
{ ZQL4<fy'E
bStop = true; ywSV4ZtM
} E$u9Jbe
';'TCb{f*
UU7E+4O&
} "-y2En
cpIFjb>u{
p3m!Iota
/* E1|>O
**FileAccess.java 5g x9W\a ?
*//文件访问(定位，写) 98c##NV(7|
package NetFox; knX*fp
import java.io.*; Ffvv8x
8vk*",
9+z5$
public class FileAccessI implements Serializable{ RFsd/K;Zp
[RAzKzC\M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Fi7G S;
RandomAccessFile oSavedFile; ">8]Oi;g
long nPos; /mi9q
\2UtT@3|C
SxX2+|0g`g
public FileAccessI() throws IOException S.: m$s
{ eT(/D/jan
this("",0); r Jo8|
} V`ODX>\
JYAtQTOR
`6R.*hq
public FileAccessI(String sName,long nPos) throws IOException [lU0TDq
{ MD"a%H#p
oSavedFile = new RandomAccessFile(sName,"rw"); NWSm
this.nPos = nPos; )aV\=a |A
oSavedFile.seek(nPos); "mbjS(-eg
} }NH\Q$IU
fXL&?~fS
QU#u5sX A
public synchronized int write(byte[] b,int nStart,int nLen) X@["Jjp
{ Z+gG.|"k
int n = -1; '8k{\>
try{ '7Ad:em
oSavedFile.write(b,nStart,nLen); ^R g=*L
n = nLen; ^|b]E
} ZqDanDM
catch(IOException e) vb&1 S
{ =XRTeIZ
e.printStackTrace (); &Zzd6[G+
} +vDEDOS1
N7wKaezE
dy}O6
return n; QbN7sg~~
} slQxz;t
cC4 2b2+
L+=pEk_
} \!*3bR
n?UFFi+a
Gp l
/* 6\+ZTw
**SiteInfoBean.java jD<fu
*/ M1Frn n
package NetFox; lc:dKGF6
(plsL
;Dw6pmZ
public class SiteInfoBean { \*wQ%_N5
~ z< &vQ=
(TX\vI&
private String sSiteURL; //Site's URL u|.c?fW'3
private String sFilePath; //Saved File's Path EgYM][:UU
private String sFileName; //Saved File's Name M0B6v}^H
private int nSplitter; //Count of Splited Downloading File LH:M`\(DL1
\68x]q[
Dc1tND$X3g
public SiteInfoBean() 2cB){.E
{//nSplitter的缺省值为5 <n+]\a97*
//default value of nSplitter is 5 x5X;^.1Fr
this("","","",5); >qqI6@h]c
} Juhi#&`T
#1-2)ZO.
_EusY3q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w!5@PJ)~U
{ D*nNu]|j
sSiteURL= sURL; .uoQ@3
sFilePath = sPath; 7A@iu*t
sFileName = sName; b|rMmx8vA
this.nSplitter = nSpiltter; odPdWV,&*
&'mq).I2
eG@0:
} Ala~4_" WL
342m=7lK
K1_]ne)
public String getSSiteURL() mDCz=pk)
{ :xBG~D
return sSiteURL; YKWiZ
} z{>p<)h
9B&fEmgEc?
W1$<,4j@M
public void setSSiteURL(String value) HCCEIgCT
{ &|'t>-de,
sSiteURL = value; en5sqKqh+
} <*Ex6/j
|e%o
l>kREfHq!{
public String getSFilePath() v/s6!3pnl
{ =_"[ &^
return sFilePath; fYt y7
} D)_67w|u|
VEc^Ap1?'
17..
public void setSFilePath(String value) <'N(`.&3C
{ 4g%BCGsys
sFilePath = value; k$NNpv&;d
} .boBo$f
J^Mq4&
v90)G8|q
public String getSFileName() C&1()U
{ }JWLm.e
return sFileName; %x]8^vze
} h{5K9$9=
h,!#YG@>
f6*6*=
public void setSFileName(String value) 1FPt%{s3
{ C||9u}Q<
sFileName = value; Hf#VW^
} 6F)^8s02h
$GI jWlAh
zZhA]J
public int getNSplitter() c97?+Y^
{ Hd8 O3_5
return nSplitter; eF06B'uL
} 2BGS$$pP
rZi\
)o;oOPT!
public void setNSplitter(int nCount) `zw^ WbCO{
{ Ocp`6Fj
nSplitter = nCount; oZ!1^o3V
} *URBx"5XZ
} `p'(:W3a
tW8&:L,m
lR8Lfa*/7
/* ^DQp9$la
**Utility.java "dItv#<:}
*/ ^{m&2l&87
package NetFox; :,f~cdq=
;dR4a@
DDwj[' R
public class Utility { A|90Ps
:p|wo"=@Ge
T!F0_<
public Utility() 5dNM:1VoE
{ d8p<f+
M#CYDEB
c2o.H!>
} n5G|OK0,
%p(!7FDE2n
//线程睡眠 ~M!9E])
public static void sleep(int nSecond) Y;uQq-CP
{ N6%wHNYZ
try{ Mnx')([;W
Thread.sleep(nSecond); S!r,p};
} p3q >a<
catch(Exception e) Fs}vI~}
{ i*\\j1mf
e.printStackTrace (); d7 W[.M$]
} vhz[H
} _=Eb:n+X
A{IJ](5.kd
//日志 +bhR[V{0g
public static void log(String sMsg) mV'XH
{ q[ -YXO
System.err.println(sMsg); ^K]`ZQjKC
} ,'%wadOo
m,X8Cy|vQ
KccIYn~
public static void log(int sMsg) e,cSB!7
{ 4Y/kf%]]A
System.err.println(sMsg); AW')*{/(Ii
} Fo:60)Lr
} ;NJx9)7<
5IJm_oy
4b/>ZHFOF;
/* m.g2>r`NU
**TestMethod.java [(kC/W)!
*/ QrSF1y'd
package NetFox; 2vLV1v$,q
L8WYxJ k
S!@h\3d8{
public class TestMethod { 4F=cER6l
/qwl;_Jcf
">|G^@|:A
public TestMethod() 1.S?(1e"
{ ///xx/weblogic60b2_win.exe OciPd/6
try{ oa;vLX$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AS-%I+ A
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xro%AM
SiteFileFetch fileFetch = new SiteFileFetch(bean); g[%^OT#
fileFetch.start(); u$%;03hJ
} pcC/$5FQ
catch(Exception e){e.printStackTrace ();} hziPHuK9,
vvwQ/iJO4Q
\nbGdka
} \96aHOk<
vLT$oiN[c
bSvr8FY3d
public static void main(String[] args) >2BWie?T
{ H)rE-7(f!
new TestMethod(); &WV&_z
} /y-eVu6
} fP>~ @^
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