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)); <V>]-bl/
} 4Zo.c* BZ
for(int i=0;i<nEndPos.length-1;i++) B[epI3R
{ Y'mtMLfMc
nEndPos = nStartPos[i+1]; =g UOHH
} RGf&KV/
nEndPos[nEndPos.length-1] = nFileLength; RG0kOw0
} -LhO </l
} J<yt/V]
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lvY[E9I0
//启动子线程 Uyj6Ij_Pj)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Xq@Bzya
for(int i=0;i<nStartPos.length;i++) n#|ljC
{ _<qe= hie!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #~BsI/m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), whxTCIV
nStartPos,nEndPos,i); .J"QW~g^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Uc^eIa@
fileSplitterFetch.start(); )%dxfwd6
} j 4!$[h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x8 _f/2&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L 4V,y>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ose(#n40
nEndPos = " + nFileLength); nm Y_)s
// fileSplitterFetch[nPos.length-1].start(); nl5A{ s
#oW"3L{,
< KGq
//等待子线程结束 E2K{9@i
//int count = 0; X|y(B%:
//是否结束while循环 vJ9I z
boolean breakWhile = false; ^m~&2l\N=
iO+,U}&
,sI<AFI
while(!bStop) x{4{.s%+:
{ WX6}@mS.
write_nPos(); 0Un?[O
Utility.sleep(500); 0$JH5RC
breakWhile = true; ^F,sV*
2. '` mGu
0xVw{k}1U
for(int i=0;i<nStartPos.length;i++) =HMa<"-8
{ M#nlKj<
if(!fileSplitterFetch.bDownOver) *,& 2?E8
{ J/LsL k
breakWhile = false; R!f<6l8#W
break; txE=AOY5
} t.y-b`v
} <yl%q*gls
if(breakWhile) z_93j3#
break; O,6Wdw3+-3
MH=7(15R
P q0%oz
//count++; .V4-
//if(count>4) (Zg'])
// siteStop(); 50_[n$tqE
} xt_:R~/[
aD]! eP/)
wg%g(FO
System.err.println("文件下载结束！"); &hEn3u
} &S,_Z/BS;
catch(Exception e){e.printStackTrace ();} "!+gA&
} {ETM >
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`AYq,3V
//获得文件长度 :of(wZa3Q
public long getFileSize() Hz\@#
{ m/z,MT74*J
int nFileLength = -1; (\0 <|pW
try{ Nv=78O1
URL url = new URL(siteInfoBean.getSSiteURL()); &1(- 8z*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XNgcBSD
httpConnection.setRequestProperty("User-Agent","NetFox"); i.k7qclL`
)fHr]#v
N=AHS
int responseCode=httpConnection.getResponseCode(); Kv<f<>|L
if(responseCode>=400) pO_IUkt
{ j$K*R."
processErrorCode(responseCode); AbxhNNK
return -2; //-2 represent access is error z',Fa4@z
} 8N%nG( 0
|BbzRis
dvZH~mF
String sHeader; (:aU"5M
AtewC Yo
D|)a7_
for(int i=1;;i++) OvAhp&k
{ +$|fUn{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W:,Wex^9n
//Utility.log(in.readLine()); ]}dQ~lOE
sHeader=httpConnection.getHeaderFieldKey(i); om`T/@_,
if(sHeader!=null) D"rbQXR7$
{ #MKM.T,\t
if(sHeader.equals("Content-Length")) #=t/wAE y:
{ T]ls&cW5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4vEP\E3u<j
break; CHsg2S
} l|=4FIMD
} +LF#XS@
else w8XCU> |
break; In?=$_p
} ;I&VpAPx
} Nai5!_'
catch(IOException e){e.printStackTrace ();} ?u|@,tQ[
catch(Exception e){e.printStackTrace ();} 4qE95THB
<q8@a0e@
q pCI[[
Utility.log(nFileLength); _]-4d_&3(
C,An\lsT
W7^[W.
return nFileLength; Xx"<^FS[zC
} G@.MP| 2
x2rAB5r6
< cvh1~>(
//保存下载信息（文件指针位置） 0V4B Q:v
private void write_nPos() n:,mo}?X
{ e"ehH#i
try{ OvtE)ul@
output = new DataOutputStream(new FileOutputStream(tmpFile)); DMM<,1
output.writeInt(nStartPos.length); 51SmoFbMz
for(int i=0;i<nStartPos.length;i++) X*QS/\
{ P(hGkY=(
// output.writeLong(nPos); X_]rtG
output.writeLong(fileSplitterFetch.nStartPos); BH">#&j[
output.writeLong(fileSplitterFetch.nEndPos); O2?C *
} 1@DC#2hPr
output.close(); >#w;67he2
} ZEAUoC1E1
catch(IOException e){e.printStackTrace ();} JVYH b 60Z
catch(Exception e){e.printStackTrace ();} ;f=m+QXU
} <eoie6@3
|^6{3a
EU$.{C_O(
//读取保存的下载信息（文件指针位置） ^U}k
private void read_nPos() t:2v`uk
{ u= NLR\
try{ Ax;=Zh<DAv
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1z?}'&:
int nCount = input.readInt(); l4>^79**
nStartPos = new long[nCount]; d9K8[Q5^3
nEndPos = new long[nCount]; qhEv6Yxfw6
for(int i=0;i<nStartPos.length;i++) ?13qDD:
{ fSkDD>&
nStartPos = input.readLong(); |_V(^b}
nEndPos = input.readLong(); `POzwYh
} y0%1YY
input.close(); q`q;og `
} rO'DT{Yt
catch(IOException e){e.printStackTrace ();} 5~L]zE
catch(Exception e){e.printStackTrace ();} =]Vz=<
} |A%9c.DG.
{KG6#/%;
<kak9 6A
private void processErrorCode(int nErrorCode) FACw;/rW
{ Z0F~?
System.err.println("Error Code : " + nErrorCode); ,#K/+T
} n0xGIq
Oynb"T&8
x HRSzYn$
//停止文件下载 bGPE0}b
public void siteStop() l/&.HF
{ LQ jbEYp
bStop = true; ={qcDgn~C
for(int i=0;i<nStartPos.length;i++) eU[g@Pq:Y
fileSplitterFetch.splitterStop(); o*S_"
\^x{NV@v42
GJ+^t
} K3T.l#d'L
} m`/Nl<
//负责部分文件的抓取 rbZbj#
**FileSplitterFetch.java @5Xo2}o-Q
*/ KdkA@>L!;
package NetFox; '5e,@t%y
\|]mClj#
C=:<[_m`
import java.io.*; 2 !s&|lI
import java.net.*; %rzPh<>e
k }=<51c
kZ40a\9 Ye
public class FileSplitterFetch extends Thread { b 7UJ
z p E|
i"^>sk
String sURL; //File URL T] zEcx+e
long nStartPos; //File Snippet Start Position ^*K=wE}AG
long nEndPos; //File Snippet End Position r|Ui1f5
int nThreadID; //Thread's ID :xd;=;q5
boolean bDownOver = false; //Downing is over . %RM8
boolean bStop = false; //Stop identical 1Kg0y71"
FileAccessI fileAccessI = null; //File Access interface f7Gn$E|/r;
)@PnpC%H
L, JQ\!c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?'a8QJo
{ JMb_00r
this.sURL = sURL; dftBD
this.nStartPos = nStart; s]arNaaA
this.nEndPos = nEnd; x:Y9z_)O
nThreadID = id; ;G[V:.o-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 22gh!F%)
} j[>cv;h ;
{/'T:n#
j(;^XO Y#
public void run() ,,H"?VO
{ :|S zD4Ag
while(nStartPos < nEndPos && !bStop) !?2)apM
{ IhnBp 6p9
$#Pxf
nhV"V`|d
try{ }^ rxsx`
URL url = new URL(sURL); RBX<>*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .E4*>@M5
httpConnection.setRequestProperty("User-Agent","NetFox"); E5k)~P`|
String sProperty = "bytes="+nStartPos+"-"; k]b*&.EY1
httpConnection.setRequestProperty("RANGE",sProperty); TdtV (
Utility.log(sProperty); -%nD'qy,.
18X@0e
zM'eqo>!c>
InputStream input = httpConnection.getInputStream(); ^Q6J$"Tj
//logResponseHead(httpConnection); Gw M:f/eV
(3#PKfY+
I \:WD"
byte[] b = new byte[1024]; &V"oJ}M/a
int nRead; ll:UIxx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZnG.::&:
{ V Z(/g"9
nStartPos += fileAccessI.write(b,0,nRead); bGRt
//if(nThreadID == 1) qQ@| Cj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WK~H]w
} hW^,' m
ajYe?z
9T,/R1N8
Utility.log("Thread " + nThreadID + " is over!"); .tBlGMcN
bDownOver = true; Cux(v8=n
//nPos = fileAccessI.write (b,0,nRead); 8{ zX=
} `Q]N]mK
catch(Exception e){e.printStackTrace ();} [$N_YcN?
} |3H+b,M5
} )2}R1K>
\2SbW7"/;P
N8<J'7%
//打印回应的头信息 )^2eC<t
public void logResponseHead(HttpURLConnection con) qd`e:s*%
{ >lI7]hbIs
for(int i=1;;i++) &w@]\7L,:
{ DaQ"Df_X
String header=con.getHeaderFieldKey(i); UKS5{"=T[
if(header!=null) v2T2/y%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lCi{v.
Utility.log(header+" : "+con.getHeaderField(header)); mU'<:gL+
else RNg?o[S
break; 96=<phcwN[
} oA1_W).wJ
} TP }a9-9?
fi+}hGj(r
Nw;qJ58@
public void splitterStop() 0|3I^b
{ 8tY>%A~^z
bStop = true; 7& M-^Ev
} {#,<)wFV\
}^"6:;,
@[GV0*yz$
} 6j#JhcS+
d2\!tJm
>{#JIG.
/* %#6@PQ[R.
**FileAccess.java fFQ|dE;cF
*//文件访问(定位，写) TlG>)Z@/
package NetFox; b#j:)PA0C
import java.io.*; 2HbnE&
Rr) 5[
B2`S0 H
public class FileAccessI implements Serializable{ }gp@0ri%5
B(Sy.n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [&x9<f6
RandomAccessFile oSavedFile; `lhw*{3A
long nPos; 8K%N7RL|
G0FzXtu)q
%mI0*YRma
public FileAccessI() throws IOException 'yo@5*x7
{ iFI74COam
this("",0); #]#9Xq
} x*7@b8J
<_?zln:4.
j,IRUx13f
public FileAccessI(String sName,long nPos) throws IOException !MbzFs~
{ [%W'd9`>
oSavedFile = new RandomAccessFile(sName,"rw"); Ufr@j` *
this.nPos = nPos; pR0[qsQM
oSavedFile.seek(nPos); ,Oo`*'a[o7
} NvK9L.K
EF/d7
eJDZ|$
public synchronized int write(byte[] b,int nStart,int nLen) z^Hc'oVXj:
{ 0<M-asI?
int n = -1; W.wPy@yi
try{ $8EEtr,!
oSavedFile.write(b,nStart,nLen); 1gI7$y+?
n = nLen; -I< >Ab
} Vk5Z[w a
catch(IOException e) C@M-_Ud>Q
{ X>(1fra4
e.printStackTrace (); ,67Q!/O
} A40DbD\^ad
>e]g T
o3WOp80hz
return n; ChBf:`e
} ,H7X_KbFD4
oFk2y^>u
"N4^ ^~s
} ?hoOSur+
A(Ct^/x-
+Y;P*U}Qg[
/* Mz+I YP`L
**SiteInfoBean.java ULx:2jz
*/ 1{uxpYAP=
package NetFox; Ple.fKu
n ]%2Kx
B|`?hw@g+
public class SiteInfoBean { 5epI'D
a@}.96lStD
iTxWXij
private String sSiteURL; //Site's URL (leX` SN0u
private String sFilePath; //Saved File's Path @N'n>8Wn
private String sFileName; //Saved File's Name [9E~=A#
private int nSplitter; //Count of Splited Downloading File ,BdObx
jkeerU6
X$};K\I
public SiteInfoBean() pn"!wqg
{//nSplitter的缺省值为5 d_[H|H9i6
//default value of nSplitter is 5 1(' wg!
this("","","",5); %-hSa~20
} uWS]l[Ga
5Ds[?
[@$ SLl^Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]:%DDlRb
{ >a3m!`lq
sSiteURL= sURL; q~`hn(S
sFilePath = sPath; 2mY!gVi
sFileName = sName; <^S\&v1C_
this.nSplitter = nSpiltter; s.1F=u9a
y6 (L=$+B
4[ uqsJB
} >`QBN1 Y
l5z//E}W
_{|a<Keq|
public String getSSiteURL() hY}Q|-|
{ zDFNx:h
return sSiteURL; GrF4*I`q
} aZZ0eH
^sv|m"
0nc(2Bi
public void setSSiteURL(String value) Ir;JYY!0?
{ Lg4|6.Ez|P
sSiteURL = value; >Eh U{@Y
} s.M39W?
T CT8OU|
74^v('-2
public String getSFilePath() Iv6 lE:)
{ FDoPW~+[
return sFilePath; txEN7!
} Z% +$<J
@&T' h}|:
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public void setSFilePath(String value) lpi"@3
{ _hnsH I!oD
sFilePath = value; #H$lBCWI
} ~EtGR # N
v^A+LZ*d
QQ?t^ptv
public String getSFileName() tPyk^NJ;
{ pPL=(9d
return sFileName; $S>'0mL
} ^f[6NYS?
P9!awLM-
he|Q(?
public void setSFileName(String value) D:`Q\za
{ Mi]^wCF
sFileName = value; $(}rTm
} w_"d&eYdg0
#1dVp!?3T
tSy 9v
public int getNSplitter() |JkfAnrN$I
{ 9hr7+fW]t
return nSplitter; "#)|WVa=BM
} /xX7:U b
f@}>:x
Z?P^Y%ls
public void setNSplitter(int nCount) jCY~Wc
{ +~n:*\
nSplitter = nCount; <NZPLo F
} #7;?Ls
} e5mu-
<^s31.&p
$yU 5WEX
/* *+v*VH
**Utility.java I<}% L V
*/ lIyMNw
package NetFox; 9L$OSy|
-!!]1\S*Y
[4?r0vO
public class Utility { ~d7t\S
?I]AE&4'
DE.].FD'
public Utility() HMVP71
{ yjT>bu]
DN:| s+Lz
{Q>OZm\+
} 20I`F>-*
2]kGDeSr
//线程睡眠 k"#gSCW$
public static void sleep(int nSecond) n1%2sV)>
{ /<_!Gz.@uG
try{ WIU]>_$.
Thread.sleep(nSecond); !<TkX/O
} zgY VB}
catch(Exception e) x[mz`0
{ xVB rwkk(
e.printStackTrace (); D%+yp
} FS}b9sQ)
} }etdXO_^
RB4n>&Y
//日志 k86TlQRh
public static void log(String sMsg) g$]WKy(D
{ t]I9[5Pq\
System.err.println(sMsg); kqX=3Zo
} np2&W'C/i
p2Khfl6-
*AV%=
public static void log(int sMsg) Uha.8
{ -]wEk%j
System.err.println(sMsg); Z*M{
} J2}poNmm
} ^EiU>
U!uPf:p2
j-d&4,a:c
/* \^6[^\@[
**TestMethod.java 2|x !~e.
*/ Hc\C0V<
package NetFox; UYxn?W.g
SY|K9$M^
o/3.U=px~
public class TestMethod { [.4{s
e1g3a1tnWl
/4O))}TX
public TestMethod() WowT!0$
{ ///xx/weblogic60b2_win.exe M(L6PyEa!Y
try{ # bHkI~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !p$p 7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); R*vQvO%)h
SiteFileFetch fileFetch = new SiteFileFetch(bean); PR5N:Bw
fileFetch.start(); |Uics:cQC
} {C&Uq#V
catch(Exception e){e.printStackTrace ();} 1UK= t
f I=G>[
dwk%!%
} tC|?Kl7
i.'"`pn_
(o*YGYC
public static void main(String[] args) 7d R?70Sz
{ d4ecF%R
new TestMethod(); w:lj4Z_
} S3/%;=|
} 1J0gjO)AZ
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