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)); 0ns\:2)cEB
} }Y~Dk]*
for(int i=0;i<nEndPos.length-1;i++) Lnr9*dm6q
{ Iux3f+H
nEndPos = nStartPos[i+1]; @Jzk2,rI
} +xFn~b/
nEndPos[nEndPos.length-1] = nFileLength; *;o%*:
} 6p9fq3~7Y
} HEF e?
g'(bk@<BP
fE-R(9K
//启动子线程 k6(7G@@}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E(jZ Do
for(int i=0;i<nStartPos.length;i++) ZEP?~zV\A
{ HL38iXQ( 3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h: ' |)O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $Habhw
nStartPos,nEndPos,i); 8QrpNSj4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j[G`p^ul
fileSplitterFetch.start(); }aZuCe_
} >HP `B2Q H
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b(iF0U>&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )kpEcMlR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", N~v6K}`}
nEndPos = " + nFileLength); wVBKVb9N
// fileSplitterFetch[nPos.length-1].start(); EuK}L[Kl
=@HS
/eF@a!
//等待子线程结束 mptFd
//int count = 0; /Z:j:l
//是否结束while循环 No^gKh24
boolean breakWhile = false; `2mddx8
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2Y vr|] \8
while(!bStop) ge~@}&#iO@
{ *]$B 9zVs!
write_nPos(); DXs an
Utility.sleep(500); :<QknU}dwy
breakWhile = true; d*@T30
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<xI<^r'C9e
for(int i=0;i<nStartPos.length;i++) X?5{2ulrI
{ 8 #_pkVQw:
if(!fileSplitterFetch.bDownOver) O=B=0
{ De?VZ2o9"
breakWhile = false; X0/slOT
break; NJUKH1lIhR
} GWA"!~Hu
} IDohv[#
if(breakWhile) b}[S+G-9W
break; 3Z!%td5n
!GcBNQ1p+7
_olQ;{ U:
//count++; y>I2}P
//if(count>4) l5[5Y6c>
// siteStop(); 2Ez<Iw
} E9:@H;Gc
#[+# bw_6
]I?.1X5d0
System.err.println("文件下载结束！"); uO%0rKW
} 2|nm> 4
catch(Exception e){e.printStackTrace ();} @N=vmtLP
} hFrMOc&
OM86C
\Kl20?
//获得文件长度 gx&es\
public long getFileSize() y|`-)fY
{ DiFLat]X
int nFileLength = -1; 9+ 'i(q z
try{ rXx#<7`
URL url = new URL(siteInfoBean.getSSiteURL()); ,\4]uZ<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c_8&4
httpConnection.setRequestProperty("User-Agent","NetFox"); <WXVUEea
x,B] J4
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int responseCode=httpConnection.getResponseCode(); (x=$b(I
if(responseCode>=400) 7KC>?F
{ HuhQ|~C+~
processErrorCode(responseCode); \YP,}_~
return -2; //-2 represent access is error E7Lqa S
} gV_v5sk
q*I*B1p[m
UU=]lWib
String sHeader; 0eY!Z._^
L2H
qO6M5g:
for(int i=1;;i++) wgl<JO
{ )Sn0Y B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $xO8?
//Utility.log(in.readLine()); ASqYA1p.
sHeader=httpConnection.getHeaderFieldKey(i); U1\7Hcs$
if(sHeader!=null) 4 m:h&^`N
{ X[BP0:`t
if(sHeader.equals("Content-Length")) kR=sr/{
{ !%>RHh[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {_9O4 + &
break; =?5)M_6)
} FnvpnU",
} GJ9>i)+h;
else yD+4YD
break; C`5'5/-.
} yl[I'fX66
} Ss[[V(-
catch(IOException e){e.printStackTrace ();} ,i:?c
catch(Exception e){e.printStackTrace ();} !XPjRdq
W[2]$TwT
Xa[k=qFo
Utility.log(nFileLength); =j.TDv'^nd
t3<MoDe7`r
sz9W}&(j
return nFileLength; bzr2Zj{4
} ]$smFF
'ZbWr*bo
2B_|"J
//保存下载信息（文件指针位置） t2[/eM.G
private void write_nPos() \VpEUU6^U
{ gAAC>{Wh
try{ -S$F\%
output = new DataOutputStream(new FileOutputStream(tmpFile)); Xa`Q;J"h
output.writeInt(nStartPos.length); 5kGniG?T#
for(int i=0;i<nStartPos.length;i++) F0$w9p
{ M(X _I`\E
// output.writeLong(nPos); wQ33Gc
output.writeLong(fileSplitterFetch.nStartPos); ] Q5:JV
output.writeLong(fileSplitterFetch.nEndPos); .psb#4
} ACRuDY
output.close(); Ht[$s40P
} &'uP?r9c$
catch(IOException e){e.printStackTrace ();} *Fy6-CC1
catch(Exception e){e.printStackTrace ();} %8*:VR
} PaCCUF
BA@E
56;u7
//读取保存的下载信息（文件指针位置） Oe5rRQ$O
private void read_nPos() $d<NN2
{ >@vu;j\*E5
try{ EGXvz)y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eHr0],
int nCount = input.readInt(); gUklP(T=u
nStartPos = new long[nCount]; K(;qdIr
nEndPos = new long[nCount]; pGs?Y81
for(int i=0;i<nStartPos.length;i++) [)"\Aq
{ }0'LKwIR
nStartPos = input.readLong(); |]7c&`
nEndPos = input.readLong(); -1Q24jrO-
} Xm#W}Y'
input.close(); SBxpJsW>
} #pvq9fss,}
catch(IOException e){e.printStackTrace ();} [F6)Z[uG
catch(Exception e){e.printStackTrace ();} 'K7\[if{
} En\@d@j<u
r=Xo;d*TE
ebBi zc=
private void processErrorCode(int nErrorCode) r8 9o
{ _vTr?jjfK
System.err.println("Error Code : " + nErrorCode); 5r5on#O&
} P@v"aa\@2)
5wue2/gl
78l);/E{v
//停止文件下载 yCQvo(V[F
public void siteStop() OAXA<
{ IxbQ6
bStop = true; lOm01&^"E
for(int i=0;i<nStartPos.length;i++) 9]eG|LFD
fileSplitterFetch.splitterStop(); VhO+nvd*W
505c(+
}O\IF}X
} C^ZoYf8+"m
} \c2x udU
//负责部分文件的抓取 ~Dt$}l-9
**FileSplitterFetch.java aM~IRLmK
*/ }u8(7
package NetFox; uWJJ\
[/a AH<9b
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import java.io.*; kL DpZ{
import java.net.*; d88A.Z3w
9~hW8{#
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public class FileSplitterFetch extends Thread { y i$+rPF1
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String sURL; //File URL Va )W[I
long nStartPos; //File Snippet Start Position %`i*SF(gV
long nEndPos; //File Snippet End Position 8\s#law
int nThreadID; //Thread's ID SJ]6_4=y*
boolean bDownOver = false; //Downing is over P!79{8
boolean bStop = false; //Stop identical (_ G>dP_
FileAccessI fileAccessI = null; //File Access interface E0!d c
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-))S
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b-ss^UL
{ ==Egy:<:Q
this.sURL = sURL; '&cH,yc;b
this.nStartPos = nStart; lp(2"$nQ
this.nEndPos = nEnd; '~Y@HRVL@|
nThreadID = id; B@*b 9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 kWW2N0~$
} -=5~h
].Yz =:
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public void run() .2&L.
{ p3vf7eqn
while(nStartPos < nEndPos && !bStop) W5Jw^,iPd
{ #1-WiweO
K 4GuOl
o8X_uKEI
try{ ht>%O7
URL url = new URL(sURL); Q/g!h}>(.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P")I)>Q6
httpConnection.setRequestProperty("User-Agent","NetFox"); t*hy"e{*a
String sProperty = "bytes="+nStartPos+"-"; ]EKg)E
httpConnection.setRequestProperty("RANGE",sProperty); [gT}<W
Utility.log(sProperty); JU17]gQ
iyn9[>je
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InputStream input = httpConnection.getInputStream(); u)<]Pb})r
//logResponseHead(httpConnection); G4'Ia$
|Y K,&
&{e ]S!D
byte[] b = new byte[1024]; ulxlh8=
int nRead; U;W9`JT<.f
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nF'YG+;|@
{ P!]uJ8bi
nStartPos += fileAccessI.write(b,0,nRead); ,]EhDW6
//if(nThreadID == 1) F`7v
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g `s|]VNt
} 0h A:=r
>Lo\?X~
>e {1e
Utility.log("Thread " + nThreadID + " is over!"); q;,lv3I
bDownOver = true; bkd`7(r
//nPos = fileAccessI.write (b,0,nRead); u@dvFzc
} <<!fA><W
catch(Exception e){e.printStackTrace ();} 'S3<' X
} 0g[ %)C
} YVccO~!8
'Ou C[$Z
.=;IdLO,Bf
//打印回应的头信息 %>$<s<y
public void logResponseHead(HttpURLConnection con) ?JZ$M
{ >eA@s}_8
for(int i=1;;i++) Dizz?O
{ nh4G;qdU
String header=con.getHeaderFieldKey(i); 7_\F$bp`
if(header!=null) !p+54w\ 2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4-.W~C'Q
Utility.log(header+" : "+con.getHeaderField(header)); WGz)-IB!PE
else opa}z-7>^
break; MS\vrq'_
} ?=9'?K/~a
} 4`i8m
)I&.6l!#
~)f^y!PMQ
public void splitterStop() p=:Vpg<!
{ ZGZNZ}~#
bStop = true; n1PptR
} }sH[_%)
N[@H107`
DURWE,W>
} ynmjIQ
- ]wT
p?f\/
/* [uU!\xe
**FileAccess.java AY5iTbL1
*//文件访问(定位，写) 6C&&="uww
package NetFox; <kFLwF?PM'
import java.io.*; [eD0L71[
0S4BV%7F
RKP,w%
public class FileAccessI implements Serializable{ y2I7Zd .
FL{?W(M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uj6'T Sl
RandomAccessFile oSavedFile; ]^C 8Oh<
long nPos; h&i*=&<HP6
1*=ev,Z
tQ{/9bN?P
public FileAccessI() throws IOException 1x|3|snz)
{ &MSU<S?1
this("",0); lBbb7*Ljt<
} }AS/^E
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5VV}wR
public FileAccessI(String sName,long nPos) throws IOException 0<%$lr
{ _P.I+!w:x
oSavedFile = new RandomAccessFile(sName,"rw"); %C_tBNE<
this.nPos = nPos; LH4A!a]
oSavedFile.seek(nPos); :$"{-n
} X6cn8ak3
[@Ac#
w6s[|i)&
public synchronized int write(byte[] b,int nStart,int nLen) 8vVE
{ +b-ON@9]J`
int n = -1; cp@Fj"
try{ wGti|7Tu*
oSavedFile.write(b,nStart,nLen); ,m<YSMKX
n = nLen; /u$'=!<b;
} ==[(Mn,%d
catch(IOException e) Ow4_0l&
{ -LiGO#U
e.printStackTrace (); Jb"FY:/Qv+
} R@K\
OV]xo8a;
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return n; Q|)>9m!tt
} %NQ%6B
? uYO]!VC
;NA5G:eQ
} `9r{z;UQ
)5b_>Uy
\( s `=(t
/* D;!sH?J@+
**SiteInfoBean.java `Xos]L'w
*/ dq '2y
package NetFox; 9}6_B|
mEJ7e#
;JkIZ8!
public class SiteInfoBean { h*VDd3[#
j~N*TXkC
H=BI%Z
private String sSiteURL; //Site's URL s^zlBvr|.
private String sFilePath; //Saved File's Path f![] :L
private String sFileName; //Saved File's Name dT0W8oL
private int nSplitter; //Count of Splited Downloading File sLA.bp.O
4<($ZN8
^^v3iCT
public SiteInfoBean() J,Ki2'=
{//nSplitter的缺省值为5 -4x! #|]
//default value of nSplitter is 5 [^ }$u[
this("","","",5); ?r !kKMZ
} sa+ JN^[X
h-PJC/>
eF%M2:&c;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9W=(D|,,
{ %:~Ah6R1
sSiteURL= sURL; edMCj
sFilePath = sPath; GUu8 N
sFileName = sName; R%3yxnM*
this.nSplitter = nSpiltter; Z@euO~e~
,C6(
p^Ey6,!8]D
} m u9,vH
z/91v#}.
6H0kY/quL|
public String getSSiteURL() f1:>H.m`
{ -Cvd3%Jje
return sSiteURL; |vd|;" `
} K-]) RIM
WblH}
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public void setSSiteURL(String value) #Tc`W_-
{ Mcc%&j
sSiteURL = value; 3DO*kM1s@
} J?{sTj"KB
6/cm TT$i
w(bvs&`{uC
public String getSFilePath() F7<M{h5s
{ +On2R&m
return sFilePath; imADjBR]
} 1CJ1-]S(3
jy~hLEt7
^N7cXK*
public void setSFilePath(String value) Srw`vql{(
{ "d-vs t5
sFilePath = value; 5dv|NLl
} 1;m?:|6K{
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\GHj_r
public String getSFileName() ]foS.D,
{ ,sj(g/hg
return sFileName; c k[uvH
} )PR`irw
<,O|fY%
+9LzDH
public void setSFileName(String value) j(I(0Yyh
{ %J6>Vc!ix=
sFileName = value; EiD41N
} 0<uL0FOT
KYkS^v
;ZJ. 7t'
public int getNSplitter() Gmu[UI}w8
{ ,^CG\);
return nSplitter; ?ZTA3mV?+
} i=^6nwD&
}qGd*k0F0
wy|b Hkr_
public void setNSplitter(int nCount) X%I@4 B7Ts
{ M`7lYw\Or!
nSplitter = nCount; @ebY_*
} N\s-{7K
} k3LHLJZ#
%a8e_
SIM>Lz
/* V,zFHXO
**Utility.java ~9YEb
*/ ?pQ0* O0
package NetFox; 'ym Mu}q
DQ$m@_/4w
l^tRy_T:-
public class Utility { a-#$T)mmfj
L
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public Utility() v\(6uej^
{ +bso4 }rS
q+qF;7dN@
[fwk[qFa
} v"Bm4+c&0
gr!!pp;
//线程睡眠 uu-M7>+
public static void sleep(int nSecond) 0WZd$
{ ^[I>#U
try{ <QgpePyoN
Thread.sleep(nSecond); sc-+?i
} !F?j'[s8]
catch(Exception e) r0f&n;0U4
{ +i /4G.=*
e.printStackTrace (); Bvj
} U$@}!X
} PXl%"O%d
Q4Wz5n1yp7
//日志 sWTa;Qi
public static void log(String sMsg) VeEa17g&
{ Rc93Fb-Zp
System.err.println(sMsg); u>] )q7s
} oG hMO
s,mt%^x[
/ZL6gRRA|
public static void log(int sMsg) $qpW?<>,0
{ lQgavP W!
System.err.println(sMsg); 2.{zfr
} vytO8m%U
} 7#&Q-3\:
J}-e9vK-#
4F -<j!
/* $Ups9pQ
**TestMethod.java i6FJG\d
*/ /Aw@26
package NetFox; =yRv*C
x'G_z_<V
[\0>@j}Z
public class TestMethod { -:!Wds
`.~*pT*u
J`; 9Z
public TestMethod() K4RQ{fWpm
{ ///xx/weblogic60b2_win.exe qm9=Ga5
try{ D#,A_GA{A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %LqT>HXJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k:mW ,s|a
SiteFileFetch fileFetch = new SiteFileFetch(bean); +~1FKLu
fileFetch.start(); A58P$#)?
} IW}Wt{'m
catch(Exception e){e.printStackTrace ();} Fo0s<YlS-
SgN?[r)
vXM{)
} 39pA:3iTd
EKuLt*a/
sw:a(o&$
public static void main(String[] args) m.gv?
{ ;Ob^@OM
new TestMethod(); ;eW)&qzK
} AYsHA w
} j5smmtM`s
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