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)); u<7/0;D#+
} *KZYv=s,u
for(int i=0;i<nEndPos.length-1;i++) ?yrX)3hyH
{ =t#llgi~
nEndPos = nStartPos[i+1]; iW]j9}t
} q 6:dy
nEndPos[nEndPos.length-1] = nFileLength; &=@IzmA
} 'Vzp2
} '1P2$#
="1Ind@w!
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//启动子线程 *)$Uvw E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .;y.]Z/;
for(int i=0;i<nStartPos.length;i++) m)ky*"(
{ ^b4 9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #px+;k5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1E[J%Rh\l
nStartPos,nEndPos,i); .KB^3pOpx
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /kZebNf6H
fileSplitterFetch.start(); O40?{v'
} s[RAHU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G, }Yl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2RVN\?s:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {g'(~ qv
nEndPos = " + nFileLength); IA fcT!{
// fileSplitterFetch[nPos.length-1].start(); g+8OekzB5
[SjqOTon{
ttaM.
//等待子线程结束 i^/T
//int count = 0; MD}w Y><C
//是否结束while循环 !j8FIY'[
boolean breakWhile = false; @+&LYy72
.Yamc#A-
bWjc'P6rx
while(!bStop) sNbxI|B
{ NlA,'`,
write_nPos(); a kkNI3
Utility.sleep(500); fF!Yp iI"
breakWhile = true; ]{;gw<T
AwCcK6N1
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for(int i=0;i<nStartPos.length;i++) z 4e7PW|
{ *^pR%E .
if(!fileSplitterFetch.bDownOver) 3<e=g)F
{ lB8-Z ow
breakWhile = false; S^JbyD_yoh
break; vOH4#
} o@_q]/Mh
} ^)470K`%)
if(breakWhile) 0.Q Ujw
break; RF?`vRZOe
v8wq,CYV
G~]Uk*M q
//count++; #JqB ;'\
//if(count>4) Zcey|m*|
// siteStop(); cRC6 s8
} ~V:\ _{mE
(fhb0i-
DcS+_>a\{l
System.err.println("文件下载结束！"); n.}ZkG0`
} A\*>TN>s
catch(Exception e){e.printStackTrace ();} W Tcw4
} `{8K.(])s!
!K#qeY}
%6t:(z
//获得文件长度 `C,n0'PL.
public long getFileSize() HRpte=`q
{ xW+6qtG`
int nFileLength = -1; 8%:Iv(UMk
try{ [XN={
URL url = new URL(siteInfoBean.getSSiteURL()); 1wii8B6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9v#CE!
httpConnection.setRequestProperty("User-Agent","NetFox"); Mg+2. 8%
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wC"FDr+
int responseCode=httpConnection.getResponseCode(); M^A48u{,"
if(responseCode>=400) X hR4ru`
{ TbMW|0 #w
processErrorCode(responseCode); 9FF0%*tGo
return -2; //-2 represent access is error {aZ0;
} xKbXt;l2
v<k?Vu
%q"%AauJR
String sHeader; ?C]vS_jAh
;2G*wR
S*pGMuui
for(int i=1;;i++) )Dms
{ HH`'*$]7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {.`vs;U
//Utility.log(in.readLine()); )w em|:H
sHeader=httpConnection.getHeaderFieldKey(i); "%)qRe
if(sHeader!=null) SV4E0c>
{ Z<oaK
if(sHeader.equals("Content-Length")) vN}#Kc\
{ W@>% {eE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xl{=Y< ;
break; 7Y lchmd
} \eTwXe]Pv
} j\yjc/m
else 0J*??g-n
break; =<C:d
} P-[-pi@
} UhF-K#Z9
catch(IOException e){e.printStackTrace ();} /*~EO{o
catch(Exception e){e.printStackTrace ();} +SzU
&/Z /Y ]
f^3*)Ni
Utility.log(nFileLength); a9e>iU
+D6YR$_<
2F[ q).
return nFileLength; E#RDqL*J
} sQ3[<
%jJG>T
Xxj- 6i
//保存下载信息（文件指针位置） z9f-.72"X
private void write_nPos() #!B4 u?"m
{ Ha#=(9.
try{ >fG3K`
output = new DataOutputStream(new FileOutputStream(tmpFile)); UsG~row:!
output.writeInt(nStartPos.length); @)F)S7
for(int i=0;i<nStartPos.length;i++) KRbvj
{ !vi>U|rh
// output.writeLong(nPos); `?H]h"{7Q
output.writeLong(fileSplitterFetch.nStartPos); 2y\E[jA
output.writeLong(fileSplitterFetch.nEndPos); umBICC]CU
} J`Q>3]wL
output.close(); &N9 a<w8+
} Cl.x'v
catch(IOException e){e.printStackTrace ();} ^S<Y>Nm]
catch(Exception e){e.printStackTrace ();} u2I*-K
} BU)U/A8iS
D>r&}6<
Z3e| UAif
//读取保存的下载信息（文件指针位置） &;6`)M{*}
private void read_nPos() O^PKn_OJ
{ J-:.FKf\5l
try{ k8yEdi`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); OF>mF~
int nCount = input.readInt(); ?PxP% $hS
nStartPos = new long[nCount]; .~db4d]
nEndPos = new long[nCount]; Y|m+dT6
for(int i=0;i<nStartPos.length;i++) *-WpZGh
{ }v;V=%N+v
nStartPos = input.readLong(); P;y45b
nEndPos = input.readLong(); mM~qBrwL
} Mexk~zA^
input.close(); t,Lrfv])
} T"Y+m-<%
catch(IOException e){e.printStackTrace ();} ^#-l q)
catch(Exception e){e.printStackTrace ();} o 11jca|
} # +>oZWVc
>=lC4Tu
qbr$>xH
private void processErrorCode(int nErrorCode) mUC)gA/
{ H'5)UX@LP
System.err.println("Error Code : " + nErrorCode); NX.6px17
} je-!4r,
%Xd[(Q)
Y Uc+0
//停止文件下载 JG.y,<xW
public void siteStop() M^Yh|%M
{ bP#:Oi0v`
bStop = true; \w>y`\6mX
for(int i=0;i<nStartPos.length;i++) "Y.tht H
fileSplitterFetch.splitterStop(); 2|y"!JqE1
m 0C@G5
hag$GX'2k
} @7c?xQVd$
} 6wRd<]C
//负责部分文件的抓取 l4YbKnp]
**FileSplitterFetch.java N% B>M7-=
*/ Es`Px_k
package NetFox; F<1fX7c
nAato\mM
nPtuTySG
import java.io.*; qwcD`HV,
import java.net.*; iMh#TUlQEQ
aK~8B_5k8
[aLI '
public class FileSplitterFetch extends Thread { ,Vax&n+J
<=&`ZH
I{&[[7H
String sURL; //File URL QL/(72K
long nStartPos; //File Snippet Start Position bWS&Yk(
long nEndPos; //File Snippet End Position A@('pA85
int nThreadID; //Thread's ID xH,a=8&9
boolean bDownOver = false; //Downing is over E=Bf1/c\
boolean bStop = false; //Stop identical {uFO/
FileAccessI fileAccessI = null; //File Access interface #z%fx
fbvL7* (
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException # w4-aJ
{ ^ +\dz
this.sURL = sURL; `RW HN/U
this.nStartPos = nStart; }v{LRRi
this.nEndPos = nEnd; MchA{p&Ol
nThreadID = id; YP<ms
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^DLfY-F+j
} |-ALklXr
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d1T!+I
public void run() ,qwuLBW
{ R\f+SvE
while(nStartPos < nEndPos && !bStop) cVpp-Z|s8
{ j;r-NCBnz
+`0k Fbx
G_JA-@i%
try{ Y@iS_lR
URL url = new URL(sURL); XT*sGM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Tidn-2L73O
httpConnection.setRequestProperty("User-Agent","NetFox"); pki%vRY
String sProperty = "bytes="+nStartPos+"-"; S hWJ72c
httpConnection.setRequestProperty("RANGE",sProperty); kZ:ZtE
Utility.log(sProperty); 8,%^ M9zBP
hfTY.
B[Scr5|
InputStream input = httpConnection.getInputStream(); ~~P5k:
//logResponseHead(httpConnection); kD%( _K5
l'qg8
gD?l-RT>
byte[] b = new byte[1024]; "k@/3
int nRead; z<;HQX,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j$:~Rek
{ uzPVTo|=
nStartPos += fileAccessI.write(b,0,nRead); qDIZJh
//if(nThreadID == 1) 3hH<T.@)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V!=,0zy~Z
} 3"i-o$P
N+xP26D8
J@'wf8Ub
Utility.log("Thread " + nThreadID + " is over!"); t{kG<J/l
bDownOver = true; e T{ 4{
//nPos = fileAccessI.write (b,0,nRead); 'H!Uh]!
} m0SlOgRsk
catch(Exception e){e.printStackTrace ();} \\qZl)P_
} X_h}J=33Q
} %> eiAB_b
8<.Oq4ku
{\5
//打印回应的头信息 L2z[
public void logResponseHead(HttpURLConnection con) n\53wh@+
{ o.!Dq7R
for(int i=1;;i++) KpGhQdR#
{ eMsd37J
String header=con.getHeaderFieldKey(i); aFYIM`?(
if(header!=null) GVn!O1jio
//responseHeaders.put(header,httpConnection.getHeaderField(header)); IJ"q~r$
Utility.log(header+" : "+con.getHeaderField(header)); NLqzi%s
else TJRCH>E[a
break; 0h_|t-9j
} cwg"c4V
} 6_Y,eL]"
Q2gq}c~
/4Gt{ygSr
public void splitterStop() fZF@k5*\
{ ez$(c
bStop = true; %h@EP[\
} :o3N;*o>)0
8ib:FF(= u
Nf\LN$ &8
} #6=
w?[upn:K
&u !,Hp
/* [W&T(%(W-
**FileAccess.java O0.*Pmt
*//文件访问(定位，写) ;=z:F<Y
package NetFox; ZECfR>`x
import java.io.*; 1qA;/-Zr<o
xJe%f\UDu
})%{AfDRF
public class FileAccessI implements Serializable{ ]f_p8?j"
2>%=U~5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o]V^};B
RandomAccessFile oSavedFile; W=?<<dVYD
long nPos; a7opCmL
g_bLl)g<
'g\4O3&_
public FileAccessI() throws IOException _[BP0\dPW
{ J&_n9$
this("",0); PJ#,2=n~
} ,P0) 6>
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TWTb?HP
public FileAccessI(String sName,long nPos) throws IOException [a(#1
{ 3v-~K)hl?
oSavedFile = new RandomAccessFile(sName,"rw"); YmG("z
this.nPos = nPos; pb,d'z\S
oSavedFile.seek(nPos); tH4B:Bgj!
} -9?]IIVb
R=?[Nz
n@3>6_^rwT
public synchronized int write(byte[] b,int nStart,int nLen) ~W/z96' 5
{ EU#^7
int n = -1; (9)Q ' 'S
try{ 6S#Cl>v
oSavedFile.write(b,nStart,nLen); l[J8!u2Xp
n = nLen; i6Gu@( 8Q
} /-s6<e!
catch(IOException e) rJB}qYD
{ #-J>NWdt
e.printStackTrace (); kx^/*~ex
} ar,7S&sH
j>kqz>3
Zd+bx*rD
return n; t{>q|0
} wd6owr
<UCl@5g&
K sCyFp
} hbn([+xY
j<$2hiI/?&
jEwIn1
/* <VE@DBWyl~
**SiteInfoBean.java !R$`+wZ62
*/ F0# 'WfM#
package NetFox; \2z>?i)
[F7hu7zY8
Ys7]B9/1O
public class SiteInfoBean { ?7A>+EY
d(K+);!
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private String sSiteURL; //Site's URL a'T;x`b8U,
private String sFilePath; //Saved File's Path 4M T 7`sr
private String sFileName; //Saved File's Name i#O SC5ZI
private int nSplitter; //Count of Splited Downloading File 7 8,n%=nG
gGuO
jiGTA:v
public SiteInfoBean() y7<|_:00
{//nSplitter的缺省值为5 E-FUlOG&
//default value of nSplitter is 5 Gm`8q}<I
this("","","",5); (k P9hcV
} QGz|*]
Nboaf
4ppz,L,4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F"kAkX>3}
{ V[V[~;Py
sSiteURL= sURL; ~6gPS 13
sFilePath = sPath; C#pjmT_
sFileName = sName; D+c>F5
this.nSplitter = nSpiltter; u&e~1?R
s#MPX3itK
=MWHJ'3-/
} sos5Y}
8CE = 4
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public String getSSiteURL() 7$#u
{ (?];VG
return sSiteURL; y>LBl]
} 8,|kao:
l"]V6!-U
tBSW|0
public void setSSiteURL(String value) YZ7.1`8
{ _dU\JD
sSiteURL = value; 62u4-}JzF
} ABkl%m6xf
sRfcF`7
r<\u6jF
public String getSFilePath() yQrD9*t&g
{ .]Z"C&"N]
return sFilePath; k=^xVQuI
} lRQYpc\
2zpr~cB=
HT@=evV
public void setSFilePath(String value) M%#e1"n
{ Va8&Z
sFilePath = value; 6B-16
} `h;[TtIX4
-qoH,4w
AwN!;t_0+N
public String getSFileName() n!(F, b
{ .^.z2 e
return sFileName; nFn5v'g
} ^Dx&|UwiZa
z{>Rc"%\
p[cX O=
public void setSFileName(String value) Pz^544\~ou
{ I:.s_8mH}
sFileName = value; EK'!}OGCG
} EV?z`jE9
]f3>-)$*
/tLVX} &
public int getNSplitter() _*zt=zn>
{ _4f;<FL
return nSplitter; hOeRd#AQK
} F!do~Z
"5 A!jq
f!"w5qC^
public void setNSplitter(int nCount) Dzbz)Zst
{ fR|A(u#9
nSplitter = nCount; Ep}s}Stlr}
} KTv$
} {b{s<@?
s@C}P
`{Ul!
/* -HuA \0J
**Utility.java /(LL3cZK
*/ <QvOs@i*
package NetFox; Mfs?x a
<}LC~B!
j#6.Gq
public class Utility { dRDnJc3
=T_g}pu
ME dWLFf
public Utility() Ls%MGs9PI
{ #b`ke/P
If.r5z9
n|;Im&,
} ~m |BC*)
BzzTGWq\
//线程睡眠 % `3jL7|
public static void sleep(int nSecond) M}Sv8D]I
{ 26nx`w?j(
try{ $^P0F9~0
Thread.sleep(nSecond); 4Up/p&1@
} z@Y;r=v
catch(Exception e) nR~(0G,H
{ C]#,+q*
e.printStackTrace (); SdWV3
} 9iq_rd]
} 6 r"<jh#
`]X>V,
//日志 kl`W\tF
public static void log(String sMsg) ,)XLq8
{ PdCEUh\>y
System.err.println(sMsg); TN.rrop`#g
} ! z**y}<T
xUvs:
Zh,71Umz
public static void log(int sMsg) P%6~&woF
{ ]A"h&`Cvt
System.err.println(sMsg); TO_e^A#
} yLGRi^d#
} q@&6#B
xmX 4qtAL
u"8yK5!
/* '7/)Ot(
**TestMethod.java OPi0~s
*/ =WLY6)]A
package NetFox; Gq6*SaTk
\8 ":]EU
R=dC4;
public class TestMethod { JLYi]nZ
U(Zq= M
]yu:i-SfP
public TestMethod() j [a(#V{
{ ///xx/weblogic60b2_win.exe _&x%^&{
try{ ;*N5Y}?j'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :Al!1BJQ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @,}UWU
SiteFileFetch fileFetch = new SiteFileFetch(bean); Bwrx*J
fileFetch.start(); u!s2BC0}N
} ;`Z{7'^U
catch(Exception e){e.printStackTrace ();} FlQGgVN
7P T{lT
==B6qX8T
} GB^Br6
edD)TpmE,
so; ]&
public static void main(String[] args) CAlCDfKW}
{ ye97!nIg@
new TestMethod(); Lr+$_ t}r
} k!^{eOM
} =%7-ZH9
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