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)); :*vSC:q
} Z6zLL
for(int i=0;i<nEndPos.length-1;i++) [x%8l,O #l
{ ]|N"jr?7H
nEndPos = nStartPos[i+1]; RA!8AS?
} 610u!_-
nEndPos[nEndPos.length-1] = nFileLength; )8taMC:H^
} hltUf5m'b
} BI<(]`FP;s
J vl-=~
BM9:|}\J65
//启动子线程 .]0:`Y,;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; RWB]uHzE
for(int i=0;i<nStartPos.length;i++) 5s%FHa
{ 2J Wp5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /!_FE+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), J|@O4g
nStartPos,nEndPos,i); )h]tKYx
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f[*g8p
fileSplitterFetch.start(); #3O$B*gV6
} &gP1=P,!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YkQ=rurE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9 ge'Mo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lmIphOUoIw
nEndPos = " + nFileLength); *&5./WEOH
// fileSplitterFetch[nPos.length-1].start(); uG+eF
k!T-X2L=
[,Y;#;
//等待子线程结束 mC$te
//int count = 0; ?es9j]
//是否结束while循环 /VFQbJ+`
boolean breakWhile = false; rcf#8
*o6QBb
MH]?:]K9V
while(!bStop) "HLh3L~
{ 5>:p'zI
write_nPos(); uG/bCb+V
Utility.sleep(500); KkJE-k*D+w
breakWhile = true; Oiw!d6"Ovq
Ko!a`I2M}
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for(int i=0;i<nStartPos.length;i++) ;[7#h8
{ cef:>>6_
if(!fileSplitterFetch.bDownOver) 'N&s$XB,
{ F)50 6
breakWhile = false; SbobXTbG
break; ?i\$U'2*z3
} }5d|y*
} "/x/]Qx2
if(breakWhile) Of nN
break; Kww+lgzS
m[w~h\FS
:UfaMe5
//count++; V.!z9AQ
//if(count>4) ^fU,9
// siteStop(); }]pOR&o
} 0Rn`63#
t&C0V|s79$
m xy=3cUi
System.err.println("文件下载结束！"); G[ q<P
} '<wZe.Q!
catch(Exception e){e.printStackTrace ();} (OG>=h8?
} CelM~W$=u
$cGV)[KWp@
O_D;_v6Ii+
//获得文件长度 InG<B,/W?
public long getFileSize() ^Uldyv/
{ 6a6N$v"
int nFileLength = -1; ?YM0VB,y
try{ UFE~6"t(
URL url = new URL(siteInfoBean.getSSiteURL()); %"3tGi:/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AVp"<Uv
httpConnection.setRequestProperty("User-Agent","NetFox"); b~+\\,q}
2!a~YT
([hd
int responseCode=httpConnection.getResponseCode(); |H8UT SX+
if(responseCode>=400) qjRp5
{ =V^8RlBi
processErrorCode(responseCode); 0[s<!k9=
return -2; //-2 represent access is error ibgF,N
} z.:IUm{z
"'c =(P
sv*xO7D.
String sHeader; g1q%b%8T
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n{E+r
for(int i=1;;i++) 1gH>B5`
{ >&|/4`HSB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oX-h7;SD
//Utility.log(in.readLine()); (PnrY~9
sHeader=httpConnection.getHeaderFieldKey(i); IUy5=Sl
if(sHeader!=null) 5{#ya2
{ ~ [=2d a
if(sHeader.equals("Content-Length")) T)cbpkH4
{ .7H*F9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `"|u NVn
break; G]I^zd&P
} ?tYc2R9x6"
} d\rs/ee
else ;hPo5uZQ
break; GnW_^$Fs
} -KCQ!0\F
} V7>{,
catch(IOException e){e.printStackTrace ();} <V*M%YWs
catch(Exception e){e.printStackTrace ();} ;<v9i#K5
{qBbzBG
o(5 (]bJ
Utility.log(nFileLength); wEIAU
7A>glZ/x
!'%`g,,r
return nFileLength; UyOoyyd.
} v:Z.8m8D
FuO'%3;c
9Dx9alJR
//保存下载信息（文件指针位置） }!Xj{Eoc
private void write_nPos() aEqDxr6
{ -cWxS{vO
try{ JOH=)+xj
output = new DataOutputStream(new FileOutputStream(tmpFile)); LwIX&\Ub
output.writeInt(nStartPos.length); e@L7p,
for(int i=0;i<nStartPos.length;i++) +DP{_x)t
{ ,9ZN k@q
// output.writeLong(nPos); w77"?kJ9X
output.writeLong(fileSplitterFetch.nStartPos); i9y&<^<W
output.writeLong(fileSplitterFetch.nEndPos); xr4kBC t
} 31}kNc}n
output.close(); zI3Bb?4.
} (yi{<$U*
catch(IOException e){e.printStackTrace ();} nYO4JlNP
catch(Exception e){e.printStackTrace ();} (B;rjpK
} V|bN<BYJ
J9/}ZD^
u:&Lf
//读取保存的下载信息（文件指针位置） G |vG5$Nf
private void read_nPos() $Z^HI
{ . vQCX1V(
try{ T>s3s5Y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JIU=^6^2'
int nCount = input.readInt(); c*x5t"{
nStartPos = new long[nCount]; )~[hf,R5S
nEndPos = new long[nCount]; (SYSw%v$A
for(int i=0;i<nStartPos.length;i++) <f`G@
{ -AxO1 qO
nStartPos = input.readLong(); [O(8izv
nEndPos = input.readLong(); <lwkjt=RV
} khtSZ"8X
input.close(); ~uz4
} 2:l8RH!Y
catch(IOException e){e.printStackTrace ();} KZSvT{
catch(Exception e){e.printStackTrace ();} )]5}d$83
} }W k!):=y
uVw|fT
yPza
private void processErrorCode(int nErrorCode) o@KK/f
{ .`K<Iug1
System.err.println("Error Code : " + nErrorCode); |Ptv)D
} o Kfm=TbY
[Dq!t1
k),.
//停止文件下载 J-g<-!>RM
public void siteStop() myeez+@ m
{ W{(q7>g
bStop = true; pT`oC&
for(int i=0;i<nStartPos.length;i++) `aW>h8$I)
fileSplitterFetch.splitterStop(); ^5sO;vf
rt[w yz8
%Cz&7qf"
} %0!!998
} td#B$$[
//负责部分文件的抓取 9vZD?6D,n
**FileSplitterFetch.java N8^AH8l
*/ -r5JP[0kP
package NetFox; Xn 1V1sr
%nfaU~IqK
kq kj.#u
import java.io.*; V>&WZY
import java.net.*; {FU,om9
[_h/DhC:+
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public class FileSplitterFetch extends Thread { 6eh\-+=
2=PX1kI
tmJ-2
String sURL; //File URL 54%@q[-
long nStartPos; //File Snippet Start Position 'dstAlt?
long nEndPos; //File Snippet End Position 0qj:v"~Q
int nThreadID; //Thread's ID #r}O =izi
boolean bDownOver = false; //Downing is over _3YuPMaN
boolean bStop = false; //Stop identical bK|I
FileAccessI fileAccessI = null; //File Access interface hY@rt,! 8
Io81zA
:"9P {xe^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $R2iSu{kO
{ yIL6Sb
this.sURL = sURL; w+NdEE4H9z
this.nStartPos = nStart; Pn*+g!`
this.nEndPos = nEnd; ROyG+dUy
nThreadID = id; As;@T$G
fileAccessI = new FileAccessI(sName,nStartPos);//定位 n@)Kf A)&
} zMf.
,33[/j
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public void run() N%k6*FBp~
{ {T^"`%[
while(nStartPos < nEndPos && !bStop) YnzhvE
{ 1sqBBd"=PY
[%alnY
'518S"T @
try{ c05kHB$O
URL url = new URL(sURL); .BR2pf|R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ([r4N#lx
httpConnection.setRequestProperty("User-Agent","NetFox"); 8tR(i[L
String sProperty = "bytes="+nStartPos+"-"; <:mV^tK
httpConnection.setRequestProperty("RANGE",sProperty); x9s7:F
Utility.log(sProperty); =skw@c^
:QGd/JX$n`
2|KgRk|!
InputStream input = httpConnection.getInputStream(); N<|_tC+ct
//logResponseHead(httpConnection); G98P<cyD
\CP)$0j-&o
ok"v`76~f5
byte[] b = new byte[1024]; [zO:[i 7
int nRead; -.>b7ui
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Nm.H
{ E*!
nStartPos += fileAccessI.write(b,0,nRead); p=7{
//if(nThreadID == 1) QU]&q`GE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fZqqU|tq
} 6fozc2h@x%
&p)]Cl/`
xpWx6
Utility.log("Thread " + nThreadID + " is over!"); X2? ^t]-N
bDownOver = true; 7<<-\7`
//nPos = fileAccessI.write (b,0,nRead); 5,I|beM
} i:6`Rmz1.
catch(Exception e){e.printStackTrace ();} $?.0>0,<
} `u zR!^X
} vU:FDkx*nn
H\Y5Fd9)
0UJ%tPS
//打印回应的头信息 WUwH W
public void logResponseHead(HttpURLConnection con) []'gIF
{ 8!~8:?6n
for(int i=1;;i++) g[]UM;D*
{ H]6i1j
String header=con.getHeaderFieldKey(i); 2qw-:
if(header!=null) Tq\S-K}4!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Fgf5OHX
Utility.log(header+" : "+con.getHeaderField(header)); 9w^lRbn
else bjQp6!TsZ
break; u?(@hUV.
} TY(B]Q_o
} raWs6b4Q
^PnXnH?
WF)(Q~op0U
public void splitterStop() G E=J Y
{ I~'%
bStop = true; $2p=vi3
} otA59 ;Z
S'Hb5C2u
Gb=pQ(n4
} KT3W>/#E
gRnn}LL^
,g.*Mx`-
/* \~sc6ho
**FileAccess.java |[/<[@\''
*//文件访问(定位，写) DChqcdx~~
package NetFox; {XHAQ9'
import java.io.*; PTU_<\
V`/E$a1&
WrA!'I
public class FileAccessI implements Serializable{ uwQ~4
PQl^jS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lO (MF
RandomAccessFile oSavedFile; [~3[Tu( C
long nPos; b`%3>
!cLdoX
Vs[A
public FileAccessI() throws IOException ',7LVT7
{ E,~|-\b}h
this("",0); `-R-O@X|
} ?IKSSe#,
eb6Ux
-6Y@_N
public FileAccessI(String sName,long nPos) throws IOException m\4V;F
{ ;Y6XX_
oSavedFile = new RandomAccessFile(sName,"rw"); nx
this.nPos = nPos; GI+x,p
oSavedFile.seek(nPos); 6:fHPlqW
} v r=va5
ans(^Up$
04K[U9W3
public synchronized int write(byte[] b,int nStart,int nLen) _d|CO
{ iS p +~
int n = -1; R[C+?qux
try{ Kyf,<zF
oSavedFile.write(b,nStart,nLen); q7}rD$
n = nLen; Y X`BX$
} / [s TN.MG
catch(IOException e) YFJw<5&
{ oZD+AF$R
e.printStackTrace (); VjI=5)+~
} 4YV0v,z
>>cb0fH5
#r=Jc8J_
return n; i\zVP.c])*
} x0KW\<k
</hv{<
`D%U5Jb
} (#&-ld6
$ Jz(Lb{
]C;X/8'Jf5
/* LD=eMk: ~
**SiteInfoBean.java 5NR@<FE
*/ 4.=jKj9j
package NetFox; ~'9\y"N1
uc<JF=
kxanzsSr9
public class SiteInfoBean { g<E[IR
HUA{ P%
bu?4$O
private String sSiteURL; //Site's URL L">\c5ca
private String sFilePath; //Saved File's Path rD\)ndPv
private String sFileName; //Saved File's Name fT2F$U
private int nSplitter; //Count of Splited Downloading File x>cl$41!W
YE*%Y["
r|_@S[hZg
public SiteInfoBean() AMw#_8Y
{//nSplitter的缺省值为5 K7 J RCLA
//default value of nSplitter is 5 Q$yMU[l)
this("","","",5); 5%_aN_1?ef
} 22T\-g{
~n"?*I`
:`>$B?x+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k-Z:z?M
{ f7SMO-3a
sSiteURL= sURL; e7Sp?>-d
sFilePath = sPath; "5!T-Z+F
sFileName = sName; \{a!Z&df
this.nSplitter = nSpiltter; KB"N',kG
9Q.@RO$%C
;*G';VuT
} ;/h&40&
&RHZ7T
'8yCwk
public String getSSiteURL() _UA|0a!-
{ 4 Aj<k
return sSiteURL; i91 =h
} ~m'8<B5+
O**~ Tj
}G)2HTaZ
public void setSSiteURL(String value) U*:ju+)k
{ oj(st{,
sSiteURL = value; 4;bc!> sfC
} SDc8\ms
LPeVr^
-N'wKT5
public String getSFilePath() F%:74.]Y
{ l*$~Y0
return sFilePath; .(&w/jR
} FVxORQI
-q]5@s/
<t&Qa~mA
public void setSFilePath(String value) b/w5K2
{ zIA)se Js
sFilePath = value; 3L CT-rp
} *iN5/w{VG
&qzy?/i8
``-pjD(t
public String getSFileName() \ iA'^69
{ jL7r1pu5
return sFileName; D#D55X^6*
} mKqXB\<
^;9<7h[l
%L|xmx!c
public void setSFileName(String value) 6)PnzeYW
{ R/xT.EQ(N
sFileName = value; js9^~:Tw
} PfsUe,*
@6 a'p
>WA'/Sl<A<
public int getNSplitter() y=aWSb2y'
{ )<f4F!?,A
return nSplitter; gN2oUbf8
} @uz(h'~
s f.z(o
va:<W H
public void setNSplitter(int nCount) )$GCur~
{ T/.UMw
nSplitter = nCount; !rF1Remw
} (hBph+
} !9{hbmF#
)MF 4b][
:-WNw n
/* 2q(gWhcj
**Utility.java 44s 9\
*/ 8`wKq6
package NetFox; D59q/@
UpPl-jeT
ZWni5uF-c
public class Utility { f62rm[
h;#046-7
5UJ ?1"J
public Utility() zBK"k]rz
{ }Q*J!OH
$) M2
ff7#LeB9
} !Eg2#a?
&8pGq./lr=
//线程睡眠 !C|Z+w9Y
public static void sleep(int nSecond) 3 l}9'j
{ %gQUog
try{ V'gJtF
Thread.sleep(nSecond); lQiw8qD
} &Z3%UOY
catch(Exception e) 8f1M6GK?
{ Bd 0oA )i
e.printStackTrace (); 5 1N/XEk
} &Nh zEl1
} +'Y?K]zbt
'7}2}KD
//日志 q7rb3d
public static void log(String sMsg) Td|u-9OM
{ Rc3!u^?u
System.err.println(sMsg); 4x}U+1B
} cIQbu#[@
8AuE:=?,,
9Zj3"v+b
public static void log(int sMsg) }& W=
{ >tPf.xI|l
System.err.println(sMsg); v%c/eAF
} 7M _ mR Vh
} zRd.!Rv
mr/?w0(C
k6J&4?xZ
/* "dGN0i
**TestMethod.java cWG%>.`5r
*/ J<0d"'
package NetFox; )HC/J-
ll1N`ke
b !y
public class TestMethod { z5oJQPPi
\NMqlxp2
C7G,M
public TestMethod() G3`9'-2q@c
{ ///xx/weblogic60b2_win.exe .%)uCLZr$
try{ x/CM)!U)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P 4t@BwU$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6Q\|8a
SiteFileFetch fileFetch = new SiteFileFetch(bean); F\&{>&
fileFetch.start(); \+nV~Pi"A
} &tvtL
catch(Exception e){e.printStackTrace ();} a]7g\rg)
NtM ?Jh
Zj-U^6^L
} 1x=x,lcL
7V8k =
ZgG~xl\My
public static void main(String[] args) *l4[`7|
{ -)^vO*b 0
new TestMethod(); #R:&Irh
} m<)`@6a/
} cfilH"EK
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