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)); \7h>9}wGf
} A#K<5%U{Mv
for(int i=0;i<nEndPos.length-1;i++) `e;r$Vpd_
{ *otgI"y\
nEndPos = nStartPos[i+1]; +qpG$#J0
} J9;fqQCt
nEndPos[nEndPos.length-1] = nFileLength; LRWM}'.s
} I.Catm2
} z3 ^_C`(F
Is6}VLbB
-B/'ArOo]
//启动子线程 S W6oaa81
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K0oF=|
for(int i=0;i<nStartPos.length;i++) V=&M\58
{ _U LzA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R#YeE`K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9D`K#3}
nStartPos,nEndPos,i); x'?p?u~[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2[=3-1c
fileSplitterFetch.start(); "~.4z,ha
} fUCjC*#1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S8kzAT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $"( 15U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CvZ\Z472.j
nEndPos = " + nFileLength); N3lz-vP-
// fileSplitterFetch[nPos.length-1].start(); %A3m%&(m&%
WB_BEh[>j
x8C\&ivn
//等待子线程结束 LibQlNW\
//int count = 0; dg~lz80
//是否结束while循环 WC=d@d)M
boolean breakWhile = false; ex`T9j.=B
~uq010lMno
F =*4]O
while(!bStop) 31 <0Nw;l
{ S"?fa)~
write_nPos(); N<b2xT
Utility.sleep(500); L58#ri=
breakWhile = true; lw~ V
K/Pw;{}
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for(int i=0;i<nStartPos.length;i++) &uc`w{,Zs
{ N.q*jY=X|
if(!fileSplitterFetch.bDownOver) k18v{)i~
{ !&b| [b
breakWhile = false; p/nATvh$
break; `9^+KK"
} <[ 2?~s
} 9.xRDk
if(breakWhile) #C.
break; s I\-0og
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?M|1'`!c8
//count++; mj9sX^$dE
//if(count>4) XC;Icr)
// siteStop(); k{vbi-^6rf
} Ye$j43b
0fvOA*UP
S2\;\?]^~
System.err.println("文件下载结束！"); {K"hlu[
} H"UJBO>$
catch(Exception e){e.printStackTrace ();} VJTO:}Q
} uY>M3h#qx
$+n6V2^K)7
`)cH(Rj
//获得文件长度 ^dk$6%0
public long getFileSize() u_+iH$zA
{ ffR%@
int nFileLength = -1; 6@8t>"}
try{ O<V 4j,
URL url = new URL(siteInfoBean.getSSiteURL()); h/{1(c}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >P@VD"U
httpConnection.setRequestProperty("User-Agent","NetFox"); JttDRNZAU
[PUu9rz#
y9d"sqyh
int responseCode=httpConnection.getResponseCode(); `#l3a
if(responseCode>=400) *-Yw%uR
{ T_D] rMl
processErrorCode(responseCode); =$)M-;6
return -2; //-2 represent access is error \$.{*f
} IaSpF<&Y;
2'-"&d+O
MYjc6@=cR
String sHeader; ojlyW})$%
+e2:?d@
4P1}XYD-2
for(int i=1;;i++) ej}S{/<*n
{ `vOL3`P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sfr+W-7kx
//Utility.log(in.readLine()); =c*l!."0
sHeader=httpConnection.getHeaderFieldKey(i); [yk-<}#B
if(sHeader!=null) F{a;=h#@Q
{ t>?tWSNf
if(sHeader.equals("Content-Length")) EZ|v,1`e
{ 4LB8p7$|a3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^5Lk}<utw
break; n6WKk+
} .S-)
} &R@([=1
else ~I+MuI[
break; s^eiymP
} =(7nl#o
} njX$?V
catch(IOException e){e.printStackTrace ();} r)}U 'iv*%
catch(Exception e){e.printStackTrace ();} aif;h! ?y
r#4/~a5i~
lD3nz<p
Utility.log(nFileLength); 37jxl+
:p: C
{LF4_9 =
return nFileLength; `wtso
} 77)WNL/ x
RM `qC
$+7uB-KsU
//保存下载信息（文件指针位置） L0!CHP/nRS
private void write_nPos() rfEWh Vy(}
{ f!#!
try{ %Rn*oV
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9)'f)60^
output.writeInt(nStartPos.length); Q7XOO3<):
for(int i=0;i<nStartPos.length;i++) wTa u.Bo
{ Is7BJf
// output.writeLong(nPos); w90YlWS#
output.writeLong(fileSplitterFetch.nStartPos); J>}J~[ap\J
output.writeLong(fileSplitterFetch.nEndPos); [DM0'4
} %k1Pyv;]
output.close(); u>"0>U
} ^r&)@R$V
catch(IOException e){e.printStackTrace ();} 7:<w)Al!
catch(Exception e){e.printStackTrace ();} *$vH]>)p
} X^ Is-[OvE
Q&I`uS=F
`nl n@ ;
//读取保存的下载信息（文件指针位置） .M^[/!
private void read_nPos() tWIJ,_8l
{ ciS,
try{ 6qH0]7maI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <R /\nYXz
int nCount = input.readInt(); GcdJf/k
nStartPos = new long[nCount]; _5-h\RB)
nEndPos = new long[nCount]; HTOr
for(int i=0;i<nStartPos.length;i++) &2`p#riAS
{ I} jgz
nStartPos = input.readLong(); 3@gsKtA&H4
nEndPos = input.readLong(); Ck Nl;g l
} a9.yuSzL
input.close(); _rwJ:r
} O9sEaVX
catch(IOException e){e.printStackTrace ();} +GI906K
catch(Exception e){e.printStackTrace ();} ~_D.&-xUF
} m|aK_
E7MSoBX9M
Z]]Ur
private void processErrorCode(int nErrorCode) BHUI1y5t
{ (jc& Fk
System.err.println("Error Code : " + nErrorCode); 2]5{Xmmo9
} {6zNCO
lhGJ/By- -
Kp`{-dUf
//停止文件下载 kUf i
public void siteStop() =:^aBN#
{ @b,Az{EH
bStop = true; }~/b%^
for(int i=0;i<nStartPos.length;i++) }uZs)UQ|$
fileSplitterFetch.splitterStop(); !ajBZ>Q
f82%nT
[k6I#v<&
} SeD}H=,@
} -&5YRfr!
//负责部分文件的抓取 C!VhVOy>d
**FileSplitterFetch.java Y_JQPup
*/ l;lrf3
package NetFox; G#n 4g:K
0X=F(,>9
J-v1"7[2GC
import java.io.*; 6c-/D.M
import java.net.*; aOwjYl[?p
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=&bI-
public class FileSplitterFetch extends Thread { ^m|@pp
l-+=Yk!X
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String sURL; //File URL 6:ettdj
long nStartPos; //File Snippet Start Position mM,HMrgLqK
long nEndPos; //File Snippet End Position I=y7$+7%
int nThreadID; //Thread's ID 0[MYQl`
boolean bDownOver = false; //Downing is over Jb QK$[z"
boolean bStop = false; //Stop identical ZZY#.
FileAccessI fileAccessI = null; //File Access interface K~TwyB-h
(~GQncqa
C^J<qq&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X-c|jn7
{ w4U,7%V
this.sURL = sURL; y{%0[x*N<m
this.nStartPos = nStart; 0gd`W{YP
this.nEndPos = nEnd; wFJf"@/vJ
nThreadID = id; 3p0v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >h\y1IrAaG
} $DL}jH^S
6 c_#"4
-s3`mc}*
public void run() xZ'fer`&
{ 'C1lP)S5
while(nStartPos < nEndPos && !bStop) ytZo0pad
{ P.Z:`P)
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!dLu($P
try{ 0k]ApW
URL url = new URL(sURL); ?jmP]MM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p F-Lz<V
httpConnection.setRequestProperty("User-Agent","NetFox"); 1q6)R/P
String sProperty = "bytes="+nStartPos+"-"; vK',!1]y
httpConnection.setRequestProperty("RANGE",sProperty); uX_H;,n
Utility.log(sProperty); o(*\MTt?
~g{j)"1
*~vB6V|1
InputStream input = httpConnection.getInputStream(); v:t;Uk^Y
//logResponseHead(httpConnection); %{u@{uG0'3
a:BW*Hy{\
)1s5vNVa
byte[] b = new byte[1024]; ^A$=6=CX
int nRead; DrJ?bG;[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m$T5lKn}U?
{ gHg=G+Q@
nStartPos += fileAccessI.write(b,0,nRead); ?I}RX~Tgg
//if(nThreadID == 1) fVbjU1N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5\Q Tm;
} p*;!5;OUR
?qgQ)#6
Y^fw37b
Utility.log("Thread " + nThreadID + " is over!"); TSB2]uH
bDownOver = true; |Y7SP]/`gB
//nPos = fileAccessI.write (b,0,nRead); 9&lemz
} r48|C{je-
catch(Exception e){e.printStackTrace ();} f3K-X1`]'U
} 7(Fas(j3
} 586P~C[ic
6TP /0o)
O$*lPA[
//打印回应的头信息 h^Wb<O`S
public void logResponseHead(HttpURLConnection con) zI`I Q
{ [:8\F#KW
for(int i=1;;i++) e?>
{ d_9 Cm@
String header=con.getHeaderFieldKey(i); 2bt>t[0ad
if(header!=null) 4^F[Gp?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j4~(6Imm
Utility.log(header+" : "+con.getHeaderField(header)); @8L5UT
else RkYdK$|K
break; Y%KowgP\
} `"5Ub,~
} +A}t_u3<
%_(vSpk
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public void splitterStop() $L*gtZ
{ q0.!T0i
bStop = true; cl& w/OJ#
} (i~UH04r>s
c4H6I~2Na
=7 l uV_5
} B2;P%B
m<CrkKfpG
7^eyO&4z
/* JipNI8\r
**FileAccess.java %3z[;&*3O
*//文件访问(定位，写) Z@bgJL83
package NetFox; y``\^F
import java.io.*; JRl=j2z
H$`U] =s|
*:%&z?<Fw
public class FileAccessI implements Serializable{ !0;AFv`\
Y{} ub]i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (TZK~+]@sb
RandomAccessFile oSavedFile; vjEDd`jYZ
long nPos; S;~eI8gQ"
'O<b'}-A
>Pw5!i\
public FileAccessI() throws IOException { DYY9MG8
{ 1Lb)S@Q`*R
this("",0); o,7|=.-b
} T?8BAxC?K
_XZ Gj:V
f"Sp.'@
public FileAccessI(String sName,long nPos) throws IOException 0#V"
{ be+-p
oSavedFile = new RandomAccessFile(sName,"rw"); 6#z8 %kaX
this.nPos = nPos; E !kN h
oSavedFile.seek(nPos); '2^}de!E
} Phn^0 iF
;Q{D]4
a\P:jgF
public synchronized int write(byte[] b,int nStart,int nLen) +XWTu!
{ ?_eLrz4>L^
int n = -1; @)pC3Vi^
try{ 9qap#A
oSavedFile.write(b,nStart,nLen); fFJ7Y+^
n = nLen; LUQ.=:mBR
} f^pBXz9&=
catch(IOException e) um9&f~M
{ ]it. R-
e.printStackTrace (); Cy-p1s
} ZF>:m>
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return n; 13?:a[~=Y
} t0e6iof^o
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[UwQi!^-O
} /stvNIEa
8a6.77c
}?2X q
/* ^Mq/Cf_T
**SiteInfoBean.java u`v&URM
*/ "Q@m7j)(
package NetFox; k$$SbStD
L?ZSfm2<
kFjv'[Y1N
public class SiteInfoBean { dA<%4_WZty
e66Ag}Sw|
4Sh8w%s
private String sSiteURL; //Site's URL ip?]&5s
private String sFilePath; //Saved File's Path qJG;`Ugl:
private String sFileName; //Saved File's Name d(^8#4
private int nSplitter; //Count of Splited Downloading File Bz'.7" ":0
P00G*iY~\
:Wbp|:N0
public SiteInfoBean() k|OM?\
{//nSplitter的缺省值为5 Do4hg $:40
//default value of nSplitter is 5 kn:hxdZ
this("","","",5); NfDS6i.Fqp
} Zj[m
ZX/FIxpy
HzM\<YD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xd{.\!q.
{ i$kB6B#==
sSiteURL= sURL; WN]k+0#
sFilePath = sPath; `)cI^!
sFileName = sName; HS|Gz3~
this.nSplitter = nSpiltter; $~5H-wJ
1gK|n
)j2#5`?"j
} B W*8
& %/p;::A
K~#?Y,}O
public String getSSiteURL() e6p3!)@P1
{ sqhMnDn[
return sSiteURL; I'xc$f_+
} J* !_O#
GP+=b:C{E
b'pwRKpx
public void setSSiteURL(String value) ;?u cC@
{ pj_W^,*/
sSiteURL = value; @PM<pEve
} D2VYw<tEA
|ru!C(
+mjwX?yF
public String getSFilePath() A\?t^T
{ T"99m^y
return sFilePath; Tu-lc)
} @95p[
J4eU6W+{
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public void setSFilePath(String value) qG,h 1
{ TDw~sxtv&
sFilePath = value; E^J &?-
} }@LIb<Y
0V6, &rTF
wfO-bzdw
public String getSFileName() o|>=<l
{ ="]lN
return sFileName; |8E~C~d
} r.)n>
Mq~E'g4#
TeuZVy8a
public void setSFileName(String value) v8F{qT50
{ dWzf C@]
sFileName = value; }t#|+T2f
} !84Lvg0&
yl?LXc[)
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public int getNSplitter() I;}U/'RR>
{ ^+-QY\N j
return nSplitter; X8v)yDtw
} a5Vlfx
{;Hg1=cm
!Gnm<|.
public void setNSplitter(int nCount) $m ;p@#n
{ l`~$cK!
nSplitter = nCount; t>quY$}4
} 6 wd
} '{0O!y[H6
P'iX?+*
1<~n2}
/* <mP_K^9c
**Utility.java 0Gj/yra9MO
*/ a1_ N~4r`
package NetFox; ()j)}F#Z`
,X|FyO(p
@[joM*U
public class Utility { rmBzLZ}
#IGcQY
27R4B O
public Utility() w*"Ii%iA<
{ /V0Put
]u<U[l-w
4 dHGU^#WZ
} EO(l?Fgw]$
?r=`Kl
//线程睡眠 t,TlW^-
public static void sleep(int nSecond) g_ep 5#\D
{ gLSI?
try{ _"F=4`lJ
Thread.sleep(nSecond); ug{sQyLN
} |:SV=T:
catch(Exception e) |Zn;O6c#L5
{ ZuWhgnp
e.printStackTrace (); e+#Oj
} jCj8XM{c>
} _[8JSw7
>9XG+f66E
//日志 >r)UDa+
public static void log(String sMsg) _s-X5xU
{ Y,mo}X<>
System.err.println(sMsg); OWz{WV.
} p\I3fI0i
U(+QrC:
_\+0e:Ae
public static void log(int sMsg) ?mV2|;
{ OWfB8*4@
System.err.println(sMsg); 9*JxP%8T~X
} fFC9:9<
} aiX4;'$x!
f dJg7r*
LDw.2E
/* -A}$5/
**TestMethod.java Yrf?|,
*/ 4]zn,g?&
package NetFox; 902A,*qq
r#j3O}(n
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public class TestMethod { QHXpX9
oT:wGBW
SANbg&$
public TestMethod() MS2/<LD3d
{ ///xx/weblogic60b2_win.exe wBI:}N@.
try{ {a>JQW5=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); UC`sq-n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?3LV$S)U
SiteFileFetch fileFetch = new SiteFileFetch(bean); uFuH/(}K[
fileFetch.start(); Pvv7|AV
} mGwJ>'+d
catch(Exception e){e.printStackTrace ();} ^eoW+OxH
R/B/|x
}#g &l*P
} #mM9^LJ
l YdATM(h
8%; .H-
public static void main(String[] args) Ozulp(8*
{ 3?gfDJfE
new TestMethod(); ]LCL?zAzH!
} $D^27q:H
} _MQh<,Z8
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