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)); ~0ZLaiJ
} a?ii)GGq
for(int i=0;i<nEndPos.length-1;i++) I DtGtkF
{ O^I%Xk
nEndPos = nStartPos[i+1]; 7Jvb6V<R
} qC$h~Epp4
nEndPos[nEndPos.length-1] = nFileLength; So\f[/em
} a>/jW-?
} %.n 7+
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S!wY6z
//启动子线程 qra5&Fvb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H:&|q+K=#
for(int i=0;i<nStartPos.length;i++) L?p,Sy<RI
{ ]U,f}T"e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *O@uF4+!1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q)b*; @
nStartPos,nEndPos,i); iPoDesp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); En]+mIEo
fileSplitterFetch.start(); ,c\3b)ax
} "lJ[H=\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H3Z"u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X6lR?6u%|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CUo %i/R
nEndPos = " + nFileLength); -H;p +XAY
// fileSplitterFetch[nPos.length-1].start(); D/= AU
_laLTP*
t/9,JG
//等待子线程结束 (`pd>
//int count = 0; V=g<3R&
//是否结束while循环 Q~p[jQ,4wZ
boolean breakWhile = false; h#iFp9N
E5}wR(i,4
<M4Qc12jP
while(!bStop) j.L`@
{ z|gG%fM
write_nPos(); yIdM2#`u
Utility.sleep(500); kTLA["<m
breakWhile = true; (YJ]}J^
+ ^9;<>P
]JXpe]B
for(int i=0;i<nStartPos.length;i++) Tpv]c
{ bl)iji`]
if(!fileSplitterFetch.bDownOver) &E>zvRBQ
{ jGtoc,\X
breakWhile = false; dU~DlaEy(
break; <2Qh5umQ
} 'h6Vj6
} "c S?t
if(breakWhile) @?GOOD_i
break; Tmo+I4qoL
I=,u7w`m
9x~qcH%
//count++; jR^>xp;
//if(count>4) nFn@Z'T$N
// siteStop(); [We(0wF[`
} m_7)r
'42P=vzo
l|[8'*]r!
System.err.println("文件下载结束！"); #]yb;L
} "/)}Cc,L
catch(Exception e){e.printStackTrace ();} 9xvE?8;M#
} [p+h b
bm{L6D E
&S.zc@rN
//获得文件长度 'CDRb3w}B
public long getFileSize() Q-[^!RAK?
{ U+!H/R)(
int nFileLength = -1; ]Qp0|45=
try{ 9's/~T
URL url = new URL(siteInfoBean.getSSiteURL()); -4p^wNR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;mXr])J
httpConnection.setRequestProperty("User-Agent","NetFox"); :v k+[PzJ
:;u~M(R
]FLuiC
int responseCode=httpConnection.getResponseCode(); )>)_>[
if(responseCode>=400) Cm;WQuv@
{ B 0%kq7>g
processErrorCode(responseCode); 2#nn}HEOC
return -2; //-2 represent access is error '|e5cW6z
} ;APpgt4
DVYY1!j<
q_8qowu"
String sHeader; K \}xb2s
yZaQ{]"
35yhe:$nf
for(int i=1;;i++) Vkex&?>v$
{ #jV6w=I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); voaRh@DZ%/
//Utility.log(in.readLine()); &X^~%\F:2
sHeader=httpConnection.getHeaderFieldKey(i); 8zz-jkR
if(sHeader!=null) FXFQ@q*}v
{ 0[0</"K%1m
if(sHeader.equals("Content-Length")) @4_CR
{ LX j Tqp'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6^['g-\2
break; ;W#G<M&n'
} *#EyfMz-B
} c0Jf
else n$}c+1
break; 0;OpT0
} W.o W=<
} z@&_3 Gl
catch(IOException e){e.printStackTrace ();} ;4XX8W1
catch(Exception e){e.printStackTrace ();} G\TyXq_4
jKQnox+=
g}' "&Y
Utility.log(nFileLength); =bf-+gZD
O" ['.b
bQ0m=BzF
return nFileLength; b#k$/A@
} fYx$3a.
!e.@Xk.P6
&e_M \D
//保存下载信息（文件指针位置） G?=X!up(
private void write_nPos() ^']xkS
{ ^fS~va
try{ 1NN99^q
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~|Gtm[9Ru
output.writeInt(nStartPos.length); F:IG3 @
for(int i=0;i<nStartPos.length;i++) VILzx+v M
{ sqac>v
// output.writeLong(nPos); :(A]Bm3
output.writeLong(fileSplitterFetch.nStartPos); &OGY?[n
output.writeLong(fileSplitterFetch.nEndPos); qN+ngk,:
} 8*4X%a=Of
output.close(); E+>Qpy
} v2JC{XqrI
catch(IOException e){e.printStackTrace ();} &bs/a]?Z7
catch(Exception e){e.printStackTrace ();} +Medu?K `
} N}VKH5U|
-`iZBC50
}I,]"0b
//读取保存的下载信息（文件指针位置） RjSVa.x
private void read_nPos() IR(JBB|xNQ
{ l5D8DvJCj
try{ =|pQA~UU#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hUB_[#8#
int nCount = input.readInt(); J03yFT,dF
nStartPos = new long[nCount]; W84JB3p
nEndPos = new long[nCount]; l>7`D3
for(int i=0;i<nStartPos.length;i++) /u*((AJ?Qv
{ & 2>W=h
nStartPos = input.readLong(); 5Ee%!Pk
nEndPos = input.readLong(); 1nX/5z_U
} )g9Zw_3
input.close(); { >bw:^F
} L@t<%fy@
catch(IOException e){e.printStackTrace ();} vv"_u=H
catch(Exception e){e.printStackTrace ();} DZilK:
} j1Q G-Rs&
ujmO'blO
vtv|H
private void processErrorCode(int nErrorCode) %mt|Dl
{ lBgf' b3$
System.err.println("Error Code : " + nErrorCode); loLQ@?E
} 5|9,S
1<\@i{;xsU
SQ1.jcWW[
//停止文件下载 co|jUDu>W
public void siteStop() 4T{+R{_Y1
{ (UAa
bStop = true; &Op, ?\
for(int i=0;i<nStartPos.length;i++) $[by)
fileSplitterFetch.splitterStop(); (es+VI2!&C
9H_2Y%_
o6'I%Gs
} \&NpVH,-
} )~rfx
//负责部分文件的抓取 {W)Kz_
**FileSplitterFetch.java hJ (Q^Z
*/ \j+O |#`|)
package NetFox; +%OINMo.A
9gZMfP
C\ZL*,%}
import java.io.*; 0~iC#lHO
import java.net.*; d(3F:dbk
r/$+'~apTk
j&6,%s-M`a
public class FileSplitterFetch extends Thread { '_lyoVP
1XSA3;ZEc
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String sURL; //File URL *p`0dvXG2
long nStartPos; //File Snippet Start Position 5Q#;4
long nEndPos; //File Snippet End Position gbsRf&4h
int nThreadID; //Thread's ID %0fF_OU
boolean bDownOver = false; //Downing is over Dd-;;Y1C
boolean bStop = false; //Stop identical w,bILv)
FileAccessI fileAccessI = null; //File Access interface o@>{kzCx
nfJ|&'T
A[oLV"J6x5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1+~JGY#
{ ;2Db/"`t
this.sURL = sURL; G~1#kg
this.nStartPos = nStart; D9zw' RY
this.nEndPos = nEnd; zpV@{%VSj
nThreadID = id; ~=h]r/b< U
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l+Dl~o}
} J]UlCg
3UU]w`At
v_)a=I%o&2
public void run() \HLI y
{ [HI&>dm=$
while(nStartPos < nEndPos && !bStop) ?v-IN
{ 5!$m3j_,]?
E1IRb':
>^LVj[.1
try{ F`SOF O
URL url = new URL(sURL); .F:qJ6E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,mEFp_a+
httpConnection.setRequestProperty("User-Agent","NetFox"); A`v(hBM
String sProperty = "bytes="+nStartPos+"-"; -ZFeE[Z
httpConnection.setRequestProperty("RANGE",sProperty); o90SXa&l/
Utility.log(sProperty); W.iL!x.B@
iwWy]V m7
<MZ$baK
InputStream input = httpConnection.getInputStream(); ZZOBMF7
//logResponseHead(httpConnection); 3t22KY[`
&f'\9lO
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byte[] b = new byte[1024]; #c@Dn.W
int nRead; "u5Hm ^H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n)uvN
{ p.^mOkpt
nStartPos += fileAccessI.write(b,0,nRead); 6NH.!}"G9
//if(nThreadID == 1) LWHP31{R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xy>wA
} x- kCNy
n"vl%!B
%^[45e
Utility.log("Thread " + nThreadID + " is over!"); rGuhYYvK
bDownOver = true; -Bbg'=QZa
//nPos = fileAccessI.write (b,0,nRead); O=LS~&=,
} wH=
catch(Exception e){e.printStackTrace ();} kCfSF%W&
} RR!(,j^M
} *vv<@+gA
7)$U>|=
NLFs)6\
//打印回应的头信息 .o91^jt
public void logResponseHead(HttpURLConnection con) (rO_Vfaa
{ qKt8sxg
for(int i=1;;i++) '#$Y:/
{ :,"dno7OQ
String header=con.getHeaderFieldKey(i); JL $6Fw;
if(header!=null) rHPda?&H
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $'e;ScH
Utility.log(header+" : "+con.getHeaderField(header)); L0uvRge
else ,{:c<W:A]
break; w{k8Y?
} 'c5#M,G~
} K y~ 9's
44FK%TmtF
IF~i*
public void splitterStop() m76**X
{ =2uE\6Fl,
bStop = true; 0/hX3h
} _d6mf4M]5
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j[NA3Vj1P
} W"Hjn/xSS
LqIMU4Ex
Ntr5Q IPd
/* &&$/>[0=.
**FileAccess.java nL!h hseH
*//文件访问(定位，写) /]%,C
package NetFox; 58zs%+F
import java.io.*; AE!WYE
S+>&O3m
MbLG8T:y
public class FileAccessI implements Serializable{ (Dn-vY'
<r\)hx0ov
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %fyb?6?Y
RandomAccessFile oSavedFile; DQ9s57VxC!
long nPos; lZua"Ju
AnyFg)a<
}(],*^'u-
public FileAccessI() throws IOException ,AD| u_pP
{ HaC3y[LJ0
this("",0); 6d.m@T6~
} P0Jd6"sS"
Xo*$|9[.
FU[,,a0<<
public FileAccessI(String sName,long nPos) throws IOException q-o>yjT~
{ 0Fw\iy1o
oSavedFile = new RandomAccessFile(sName,"rw"); 1Efl|lV
this.nPos = nPos; ljis3{kn""
oSavedFile.seek(nPos); n=SZ8Rj7
} f|G7L5-
@uE=)mP@
'|/_='
public synchronized int write(byte[] b,int nStart,int nLen) &B2c]GoW
{ T7T!v
int n = -1; "@?|Vv,vn
try{ :^s7#4%6
oSavedFile.write(b,nStart,nLen); M"vcF5q
n = nLen; u7C{>
} 8(KfX%
catch(IOException e) 0;H6b=
{ (XwLKkw0n
e.printStackTrace (); =qtoDe
} 0V#t ;`Q3
/T(\}Z
w.Vynb
return n; 9v F2aLPk
} 5Hm!5:ZB
0xxzhlKNL
@NNLzqqY
} cORMR!
+.lWck
D,n}Qf!GYk
/* U&n>fXTHn
**SiteInfoBean.java ;F""}wzn
*/ !~N4}!X3du
package NetFox; .lBY"W&{
Vrj1$NL%
fBgKX?Y
public class SiteInfoBean { MH.,s@
YU=ZZEVi
qZJ*J+
private String sSiteURL; //Site's URL w;EXjl;X O
private String sFilePath; //Saved File's Path 0Mu8ZVI{
private String sFileName; //Saved File's Name Dw=Z_+J
private int nSplitter; //Count of Splited Downloading File @5jG
"x;k'{S
ewrWSffe
public SiteInfoBean() 6eT'[Umx
{//nSplitter的缺省值为5 eqZ+no
//default value of nSplitter is 5 a9Fm Y`
this("","","",5); 5g1M_8e'+
} 3rdfg
qggk:cN1
43>9)t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |[Ie.&)
{ lU$4NUwM
sSiteURL= sURL; g. ?*F#2
sFilePath = sPath; /S]:dDY9K
sFileName = sName; qB F!b0lr
this.nSplitter = nSpiltter; V3mjbH>F
S\9t4Ki_'
I f3{E
} * -KJh_
c6,s+^^
%o@['9U[j
public String getSSiteURL() 9q1HSJ1)
{ " ^HK@$
return sSiteURL; :}@C9pqr2
} "{A*(.
rGnI(m.
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public void setSSiteURL(String value) uC,"5C
{ Z5G]p4
sSiteURL = value; YlswSQ
} AH2_#\
*jM_wwG
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public String getSFilePath() fJN*s
{ DW/1 =3
return sFilePath; PiMKu|,3
} d/D,P=j"
_wf5%(~b
{=UFk-$=
public void setSFilePath(String value) M1oPOC\0.
{ YD&|1h
sFilePath = value; /g_9m
} Y^52~[w~
eV"!/A2:N5
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public String getSFileName() U1ZIuDg'E
{ lVPOYl%
return sFileName; ^SZw`]
} :e*DTVv8
wfgqgPo!v
opsQn\4DZ?
public void setSFileName(String value) dj'm, k b
{ NJtQx2Sd'H
sFileName = value; z{9=1XY
} w|IjQ1{
veeI==]
*G9sy_
public int getNSplitter() i AdGgK
{ ~q)u(WC|
return nSplitter; zuSq+pxL@
} .evbE O5
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07V8;A<,
public void setNSplitter(int nCount) hi ~}
{ x2co>.i
nSplitter = nCount; hoa7
} 8WL8/
} j[I`\"
98RKCc9h
X'f.Q
/* ';0 qj$#
**Utility.java #]CFA9z
*/ #2RiLht
package NetFox; +k.%PO0np
y}FZD?"
Z:*@5
public class Utility { $=B8qZ+
!M7<BD};
8S]".
public Utility() \P;rES'
{ g:7,~}_}^
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~ Vw9
} LJFG0 W
Ml?~ |_
//线程睡眠 .1yT*+`
public static void sleep(int nSecond) %c|UmKKi
{ IvHh4DU3Z
try{ zce`\ /:
Thread.sleep(nSecond); R'}95S<
} 7j$Pt8$
catch(Exception e) :O-iykXyI
{ 7y^%7U \
e.printStackTrace (); {2&m`Dbm
} ,](:<A)W&
} K+Y^>N4m
oVvc?P
//日志 69m ;XdkKz
public static void log(String sMsg) 6at1bQ$
{ 3S*AxAeg
System.err.println(sMsg); ^qGb%! l
} ^n1%OzGK#
0 B@n{PvR0
z~*g~RKS!
public static void log(int sMsg) g.py+ ZFJ
{ = ?D(g
System.err.println(sMsg); m: n`g1
} )s_n
} dCyqvg6u
=m89z}Ot
{\H/y c|@
/* +mj*o(
**TestMethod.java ^I8Esl8
*/ Fm\"{)V:b
package NetFox; %nN `|\
qgIb/6;xQ
>Y7a4~ufko
public class TestMethod { [.se|]t7X
PZxAH9 S?
-fhN"B)
public TestMethod() K<?nq0-
{ ///xx/weblogic60b2_win.exe <q*oV
try{ **9x?s
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^;!0j9"*:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j',W 64
SiteFileFetch fileFetch = new SiteFileFetch(bean); v+p{|X-
fileFetch.start(); {3;AwhN0H
} fjvN$NgVs
catch(Exception e){e.printStackTrace ();} V7#v6!7A@
EA ]+vq
Lg8nj< TF
} Uc/+gz Z;
8!.ojdyn
zvABU+{jD
public static void main(String[] args) DZzN>9<)^
{ :0Z^uuk`gq
new TestMethod(); g^*<f8 ~d
} <: &*
} r0p w_j
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