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)); n@G[
} >ooZj9:'
for(int i=0;i<nEndPos.length-1;i++) qTQBt}
{ Z(!00^
nEndPos = nStartPos[i+1]; o6//IOZ
} sN5B7)Vc
nEndPos[nEndPos.length-1] = nFileLength; CW<N: F.9
} wb~@7,D
} W0}B'VS.I
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c_elShK8#
//启动子线程 MTUn3;c/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O(_[ayE
for(int i=0;i<nStartPos.length;i++) &5:tn=E
{ (e"iO`H
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^n+!4(@=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [k-+AA>:
nStartPos,nEndPos,i); >$2V%};
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "le>_Ze_>|
fileSplitterFetch.start(); p0pWzwTG3
} tY <Z'xA?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VcoOeAKL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *_?dVhxf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0:b2(^]bg
nEndPos = " + nFileLength); Gm\/Y:U
// fileSplitterFetch[nPos.length-1].start(); Gdg"gi!4
Ge<nxl<Bd
3N_"rNKD
//等待子线程结束 Bp@v,)8*
//int count = 0; a+Ac[>
//是否结束while循环 wgw(YU
boolean breakWhile = false; 'R_g">B.
<^$<#Kd
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while(!bStop) 8.[SU
{ T*KMksjxm`
write_nPos(); K#"O a h
Utility.sleep(500); )&!&AlLn
breakWhile = true; 5ls6t{Ci
__.+s32SS$
Xn{1 FJX/
for(int i=0;i<nStartPos.length;i++) ` Jdb;
{ ~s5SZK*
if(!fileSplitterFetch.bDownOver) %HJK;
{ %plo=RF
breakWhile = false; 7.`fJf?
break; db6mfxi
} 1/"WD?a
} I(XOE$3
if(breakWhile) h*v8#\b$J_
break; _8E/)M
&%-73nYw
^#sU*trr
//count++; QqU!Najf
//if(count>4) !/wtYI-`
// siteStop(); mrw=T.
} S9#)A->
h2D>;k
%Z1N;g0
System.err.println("文件下载结束！"); s~Te
} bcYF\@};
catch(Exception e){e.printStackTrace ();} [1u-Q%?#
} Gn&4V}F
cCxBzkH6
p3^m9J
//获得文件长度 ,S!azN=
public long getFileSize() }+sT4'Ah>
{ F|!){=
int nFileLength = -1; 1@-Ns
try{ \P6$mh\T
URL url = new URL(siteInfoBean.getSSiteURL()); L+i(TM=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /~<@*-'
httpConnection.setRequestProperty("User-Agent","NetFox"); |)*fRL,
q*9!,!e
LSRk7'0
int responseCode=httpConnection.getResponseCode(); b1($R[
if(responseCode>=400) 7"C$pm6
{ =y!$/(H
processErrorCode(responseCode); g pOC`=
return -2; //-2 represent access is error c??mL4$'N
} ruy}/7uf
\*<d{gZ~
`V04\05
String sHeader; >m$ 1+30X
&e!7Z40w@&
SBS3?hw
for(int i=1;;i++) kbe-1 <72
{ {Ja!~N;3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \QCJ4}\CS
//Utility.log(in.readLine()); Dbz3;t
sHeader=httpConnection.getHeaderFieldKey(i); 7yh/BZ1
if(sHeader!=null) aSnFKB
{ eYvWZJa4
if(sHeader.equals("Content-Length")) @ rc{SB
{ %B.yW`,X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); HKUn`ng
break; b"{'T]"*j
} (P:<t6;+
} #n8IZ3+
else $F5 b
break; bXNk%W[n
} {Sj9%2'M)
} (:>,u*x%
catch(IOException e){e.printStackTrace ();} Bn &Ws
catch(Exception e){e.printStackTrace ();} 1bn^.768l
736Jq^T
XSyHk"g`
Utility.log(nFileLength); ?o|f':
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#iHs* /85
return nFileLength; O[ef#R!
} TJR:vr
fNW"+ <W
0a XPPnuX
//保存下载信息（文件指针位置） ]Yn_}Bq
private void write_nPos() Y<%@s}zc
{ UWo]s.
try{ '?p<lu^^B
output = new DataOutputStream(new FileOutputStream(tmpFile)); XLrwxj0
output.writeInt(nStartPos.length); }*S `qW;B
for(int i=0;i<nStartPos.length;i++) $arK(
{ YF>m$?;
// output.writeLong(nPos); %#xaA'? [
output.writeLong(fileSplitterFetch.nStartPos); 2$ze= /l
output.writeLong(fileSplitterFetch.nEndPos); 9~/J35
} <"my^
output.close(); '$ t
} /Y2}a<3&0
catch(IOException e){e.printStackTrace ();} U ^5Kz-5.
catch(Exception e){e.printStackTrace ();} hJpxf,?'K
} A"dR{8&0
P 'od`
hFy;ffs.
//读取保存的下载信息（文件指针位置） DrY:9[LP
private void read_nPos() ^Dn D>h@q
{ :7]Sa`
try{ [R^iF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ay0U=#XP
int nCount = input.readInt(); WGZ9B^A
nStartPos = new long[nCount]; jYmR
nEndPos = new long[nCount]; %|q>pin2
for(int i=0;i<nStartPos.length;i++) sl`s_$J
{ st:`y=F_
nStartPos = input.readLong(); os:A]
nEndPos = input.readLong(); 0vD7v
} S]Mw#O|
input.close(); sg3OL/"
} T^k7o^N>
catch(IOException e){e.printStackTrace ();} E^/t$M|H
catch(Exception e){e.printStackTrace ();} 'O_3)x5
} gf &Pn
1;Cyz)
LcTt)rs f
private void processErrorCode(int nErrorCode) Ch|jtVeuyJ
{ f$Fhf?'
System.err.println("Error Code : " + nErrorCode); Pama#6?OPh
} qGB{7-ru
yDegcAn?
f=r<nb'H
//停止文件下载 -~v2BN/
public void siteStop() %4,O 2\0?&
{ pm 9"4z
bStop = true; F`XP@Xx
for(int i=0;i<nStartPos.length;i++) 9CWF{"
fileSplitterFetch.splitterStop(); "8x8UgG
iXVe.n
1AM!8VR2
} *U,@q4
} \F/hMXDlJ
//负责部分文件的抓取 x7!L{(E3
**FileSplitterFetch.java WrxP
*/ d"*uBVzXm
package NetFox; --HZX
H Y&DmE
'$ =>
import java.io.*; Mh:L$f0A%O
import java.net.*; emqZztccZ
6z#acE1)M
p'*>vk
public class FileSplitterFetch extends Thread { G\Cp7:j}
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wnEyl[ac
String sURL; //File URL "$+Jnc!!
long nStartPos; //File Snippet Start Position lm-dW'7&
long nEndPos; //File Snippet End Position |Mup8(gCk
int nThreadID; //Thread's ID [B#R94
boolean bDownOver = false; //Downing is over ;o2$ Q
boolean bStop = false; //Stop identical m.# VYN`+A
FileAccessI fileAccessI = null; //File Access interface bYpntV
hKLCJ#T
|,gc_G
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e,vvzso
{ 1PQ~jfGi
this.sURL = sURL; .f%fHj
this.nStartPos = nStart; K1"*.\?F
this.nEndPos = nEnd; ?(Dq?-.
nThreadID = id; VM GS[qrG
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RKHyw08
} (2J: #
c'>/
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public void run() PV'x+bN5
{ |:nOp(A\*
while(nStartPos < nEndPos && !bStop) m? J0i>H
{ 4o <Uy
u~7hWiY<2
H]{v;;'~
try{ C*)3e*T*
URL url = new URL(sURL); r3&G)g=u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |[<_GQl
httpConnection.setRequestProperty("User-Agent","NetFox"); U@_dm/;0&
String sProperty = "bytes="+nStartPos+"-"; EUD~CZhS"k
httpConnection.setRequestProperty("RANGE",sProperty); , pDnRRJ!
Utility.log(sProperty); %p^wZtm
8=B|C'>
:DrWq{4
InputStream input = httpConnection.getInputStream(); `w#Oih!6A|
//logResponseHead(httpConnection); "pi=$/RD9
+7D|4
0=@?ob7
byte[] b = new byte[1024]; C%$edEi
int nRead; [')m|u~FS4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "CSsCA$/
{ #^lL5=
nStartPos += fileAccessI.write(b,0,nRead); QUq_:t+Dv
//if(nThreadID == 1) L[oui,}_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D.B.7-_8
} s@&`f{
'y;EhOwj,
sT3^hY7
Utility.log("Thread " + nThreadID + " is over!"); -BrMp%C
bDownOver = true; _E&A{HkJ
//nPos = fileAccessI.write (b,0,nRead); `18qbot
} [;4g
catch(Exception e){e.printStackTrace ();} m,*QP*
} nt 81Bk=
} $UMFNjL
Ygm`ZA y
eJF5n#
//打印回应的头信息 a,@]8r-"
public void logResponseHead(HttpURLConnection con) >:AARx%
{ XX7{-Yy
for(int i=1;;i++) {@H6HqD
{ yzbx .
String header=con.getHeaderFieldKey(i); FOv=!'So
if(header!=null) *W4m3Lq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9_# >aOqL
Utility.log(header+" : "+con.getHeaderField(header)); [pC$+NX
else 3c#BKHNC
break; %+@O#P
} ypbe!Y<i]
} m!|kW{B#A
nW PF6V>
_GXk0Ia3`
public void splitterStop() j~2{lCT
{ 5gb|w\N>
bStop = true; [.O?Z=5a[V
} YZLkL26[
.f*4T4eR-
,~aQL
} [;r)9mh7
9=vMgW
WKts[Z
/* bZnuNYty75
**FileAccess.java mC4zactv
*//文件访问(定位，写) e}D3d=6`
package NetFox; S@jQX
import java.io.*; K,Ef9c/+K
:8L8q<U
chcbd y>C
public class FileAccessI implements Serializable{ 14Xqn8uOW
dT`D:)*:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6CV* Z\b
RandomAccessFile oSavedFile; |jQ:~2U|
long nPos; @)UZ@ ~R
8ZM?)#`@{
5m*iE*+
public FileAccessI() throws IOException :}Xll#.,m
{ j| v%)A
this("",0); v0 nj M
} Upc+Ukw
fL_4uC i\
wg7V-+@i
public FileAccessI(String sName,long nPos) throws IOException zcel|oz)
{ @GBxL*e
oSavedFile = new RandomAccessFile(sName,"rw"); Sc>,lIM
this.nPos = nPos; S'|,oUWDb
oSavedFile.seek(nPos); bV(Y`g
} ujDd1Bxf?
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_K`wG}YIE
public synchronized int write(byte[] b,int nStart,int nLen) $*SW8'],`
{ AJf4_+He
int n = -1; 00G%gQXk,
try{ Vr)<\h
oSavedFile.write(b,nStart,nLen); b=g8eMm
n = nLen; GQt8p[!
} gD,1 06%
catch(IOException e) O-ew%@_
{ H2&@shOOQJ
e.printStackTrace (); LM$W*
} I(]}XZq
98j>1"8
~T ]m>A!
return n; 88VZR&v
} O,J>/
8J=?5
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} xe#FUS 3
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GS0;bI4ay
/* o}$XH,-9&
**SiteInfoBean.java aK&b{d
*/ W,4QzcQR
package NetFox; '= _/1F*q
NiWa7/Hr
;'?l$ ._
public class SiteInfoBean { kjW+QT?T&
ZO!I.
Qt iDTr
private String sSiteURL; //Site's URL <A[E:*`*
private String sFilePath; //Saved File's Path ~"!] 3C,L
private String sFileName; //Saved File's Name :H7D~ n
private int nSplitter; //Count of Splited Downloading File "JVkVp[5D+
ks3`3q 7
TMAJb+@l:
public SiteInfoBean() l,R/Gl
{//nSplitter的缺省值为5 XxT#X3D/,"
//default value of nSplitter is 5 qd9cI&
this("","","",5); vqnw#U4`
} Ipf|")*
Da&vb D-Bg
,LTH;<zB)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VGfMN|h
{ @x9a?L.48
sSiteURL= sURL; 0Oi,#]F
sFilePath = sPath; `k=bL"T>\
sFileName = sName; {FO;Yg'
this.nSplitter = nSpiltter; E'v_#FLvR
{kp-h2I,
q`|LRz&al
} x9$` W
_.>QEh5"5
2{]`W57_=
public String getSSiteURL() #,S0HDDHn
{ P::TO-C
return sSiteURL; 9iXeBC
} G3{Q"^S"
rFIqC:=
BS /G("oZ[
public void setSSiteURL(String value) ^g*pGrl#
{ 4oK?-|=?
sSiteURL = value; .clP#r{U
} guX 9}
W@T~ly;e*
/+8JCp
public String getSFilePath() $iI]MV%=
{ QBtnx[
return sFilePath; l=]cy-H
} aY3^C q(r
v$~QU{&
?;KKw*
public void setSFilePath(String value) lwHzj&/ ~
{ +)kb(
sFilePath = value; UUSq$~Ct
} _6O\W%it
bnm P{Ps
D Gr> 2
public String getSFileName() BsBK@+ZyI
{ yN~dU0.G6!
return sFileName; ^w(p8G_-w
} s<*XNNE7
7bqBk,`9
7]^M>#
public void setSFileName(String value) (>F%UY
{ SLO%7%>p
sFileName = value; 6Ca(U'
} C2@,BCR
Ol1e/Wv
=6woWlfb
public int getNSplitter() F4It/
{ 4?0vso*X<:
return nSplitter; ">~.$Jp_4
} 7Ok;Lt!x
2}YOcnB
.nG#co"r}3
public void setNSplitter(int nCount) SPN5dE.@
{ "vXxv'0\f
nSplitter = nCount; Tg!i%v(-t
} xG}(5Tt
} !O-T0O
I'PeN0T f
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/* ;} und*q
**Utility.java kdCUORMK
*/ fYp'&Btb]x
package NetFox; @[5xq
J%x6
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public class Utility { JXCCTUO
"[vu6`m?
y|CP;:f;
public Utility() EPS={w$'s
{ W.z;B<
~vs}.kb
QF{4/y^j{
} %{YN70/
;w'D4p= P
//线程睡眠 [`p=(/I&L
public static void sleep(int nSecond) MxWy*|J}
{ bSsh^Z
try{ *\=.<|HZ
Thread.sleep(nSecond); ~GTz:nC*
} h]og*(
catch(Exception e) 4$qWiG~
{ ELBa}h;
e.printStackTrace (); ,z3{u162
} "J+3w
} ~2<7ZtV=
]d,S749(s
//日志 >2~+.WePu
public static void log(String sMsg) uvtF_P/
{ u`y><w4i
System.err.println(sMsg); J\d3N7_d
} %FXfqF9
ObLly%|i
I"Ms-zs
public static void log(int sMsg) #?q&r_@@
{ j;s"q]"x]
System.err.println(sMsg); !6s"]WvF
} b'J'F;zh>
} /DQc&.jK
M%1}/!J3
Q>/C*@
/* A/s>PhxV
**TestMethod.java D<8HZ%o
*/ AK\$i$@6
package NetFox; +|bmT
AgV G`q
>y.%xK
public class TestMethod { R&|mdY8
t<~$
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public TestMethod() dY@WI[yog
{ ///xx/weblogic60b2_win.exe uwa~-xX6
try{ vJ\pR~?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0@G")L Ue0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b7!Qn}
SiteFileFetch fileFetch = new SiteFileFetch(bean); r`AuvwHPs[
fileFetch.start(); 6b%WHLUeT
} ^xh}I5
catch(Exception e){e.printStackTrace ();} .mDM[e@'
/I)yU>o
Q2zjZC*'%
} } @K FB
`D`sr[3n
[[>wB[w
public static void main(String[] args) I4i2+ *l}
{ *g y{]
new TestMethod(); j7sKsbb
} 0G7K8`a
} u}!@ ,/)
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