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)); a|]%/[G@
} 4cVs(`g^
for(int i=0;i<nEndPos.length-1;i++) cx1WGbZ
{ R4Gg|Bh
nEndPos = nStartPos[i+1]; mBD!:V'
} EP*["fx
nEndPos[nEndPos.length-1] = nFileLength; "0!eb3n
} Ztpm_P6
} uP%;QBb
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i\DHIzGp[
//启动子线程 U#~nN+SIt
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X-;Qorb^
for(int i=0;i<nStartPos.length;i++) #%=vy\r
{ X'3`Q S:!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'nj&}A'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4LB9w21
nStartPos,nEndPos,i); .$ P2W0G
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EU&3Pdnd
fileSplitterFetch.start(); rz%[o,s
} =J[[>H'<d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YCLD!S/?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u;'<- _
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L]L~TA<D9i
nEndPos = " + nFileLength); _QOOx+%*5
// fileSplitterFetch[nPos.length-1].start(); {eD>E(Y@z1
.xc/2:m9
61Iy{-/ZV
//等待子线程结束 :v WYII7
//int count = 0; A86lyBDQ*
//是否结束while循环 #&`WMLl+8
boolean breakWhile = false; %]:vT&M
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Pu\DYP:(
while(!bStop) (82\&dfy
{ g$^qQs)^N
write_nPos(); SUnmp
Utility.sleep(500); v BeU
breakWhile = true; &T{B~i3w8
f29HQhXqS
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for(int i=0;i<nStartPos.length;i++) *a0I Z
{ Mpl,}Q!c
if(!fileSplitterFetch.bDownOver) vdFQf ^l
{ 5P t}
breakWhile = false; B| 0s4E
break; XL&eJ
} e#eO`bT
} )}9}"jrDlx
if(breakWhile) ZD] '$
break; mX_Uhpw?t
H1ui#5n2
g2b4 ia!L
//count++; &#b>AAx$2Y
//if(count>4) !CMVZf;u
// siteStop(); {arjW3~M:
} rM~IF+f0XD
K|J#/
]O(HZD%
System.err.println("文件下载结束！"); 96V, [-arf
} uKAHJ$%
catch(Exception e){e.printStackTrace ();} HE<%d
} AJ1$$c
pS)X\Xyw
P}u<NPy3Q
//获得文件长度 bDh(;%=
public long getFileSize() `3s-%>
{ (L
int nFileLength = -1; I$qtfGr
try{ +CHO0n
URL url = new URL(siteInfoBean.getSSiteURL()); qmeEUch`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uH;^>`DT
httpConnection.setRequestProperty("User-Agent","NetFox"); =&G|} M
#7:9XID /
xMGd'l?
int responseCode=httpConnection.getResponseCode(); ]mU*Y:<
if(responseCode>=400) &CsBG?@Z|
{ >t<R6f_Q0
processErrorCode(responseCode); xF>w r r
return -2; //-2 represent access is error ',ybHW%D%i
} tZ2iSc
jM@I"JZb
lxJ.h&"P
String sHeader; O6 J<Lqgh
2Yf;b9-k
[GT1,(}. Z
for(int i=1;;i++) mZ&Mj.0+~
{ uUB%I 8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g}j>;T
//Utility.log(in.readLine()); J)&+y;.
sHeader=httpConnection.getHeaderFieldKey(i); Y]Nab0R&
if(sHeader!=null) t/BiZo|zl
{ 1pr_d"#4
if(sHeader.equals("Content-Length")) juZ3""
{ qk"=nAJX
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,Yt&PE
break; Yx/~8K_%M?
} .F|WQ7Mu
} TBp5xz`
else AUpC HG7
break; JKbB,
} Mo=-P2)>lt
} 9!C?2*>A P
catch(IOException e){e.printStackTrace ();} X~4:sJ\P=
catch(Exception e){e.printStackTrace ();} 4hz,F/ I
~ZC=!|Q#
hiM!htc;M
Utility.log(nFileLength); @_nhA/rlc
*9&YkVw~
Q1B!W
return nFileLength; (R,n`x2^
} Om~C0
J#WPXE+Ds
7FFYSv,[:
//保存下载信息（文件指针位置） {q4"x5|
private void write_nPos() ,DZLEsFM
{ AVZ@?aJgF
try{ " <AljgF
output = new DataOutputStream(new FileOutputStream(tmpFile)); Sw)ftC~d
output.writeInt(nStartPos.length); 03;(v%
for(int i=0;i<nStartPos.length;i++) /LzNr0>2
{ =w>QG{-N
// output.writeLong(nPos); #pFybk
output.writeLong(fileSplitterFetch.nStartPos); S5!2%-;<k
output.writeLong(fileSplitterFetch.nEndPos); )Ggx
} gJ7puN
output.close(); ;zG|llX
} R6Lr]H
catch(IOException e){e.printStackTrace ();} > `M\xt
catch(Exception e){e.printStackTrace ();} S>Y?QQ3#wp
} Ymvd=F
gk`.8o
VG^-aR_F
//读取保存的下载信息（文件指针位置） S22;g
private void read_nPos() uIwyan-
{ lEs/_f3;A
try{ 3!x)LUWfWY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )9->]U@
int nCount = input.readInt(); de=T7,G#
nStartPos = new long[nCount]; LlqhZetS
nEndPos = new long[nCount]; .&dcJh*O+
for(int i=0;i<nStartPos.length;i++) p}uw-$O
{ (*tJCz`Sj
nStartPos = input.readLong(); UW3F)
nEndPos = input.readLong(); ^j7pF.j
} {BU,kjv1g
input.close(); D bJ(N h
} 35T7g65;
catch(IOException e){e.printStackTrace ();} 7h~M&\M
catch(Exception e){e.printStackTrace ();} VPbNLi
} 2XpGgG`2`C
*PPFk.#x
1[ Pbsb
private void processErrorCode(int nErrorCode) Q1yTDJ(2
{ C5z4%,`f
System.err.println("Error Code : " + nErrorCode); Y._AzJ&B[
} 70~]J8T+u
na)_8r~
<^paRKEa+#
//停止文件下载 {HeMdGn9
public void siteStop() kOO2 ?L|Z
{ "'L SLp
bStop = true; zx*f*L,6F
for(int i=0;i<nStartPos.length;i++) ]&>)=b!,
fileSplitterFetch.splitterStop(); #96a7K
;Wdo*ysW
40XI\yE_?
} XRkqMq%
} Jt"Wtr
//负责部分文件的抓取 V96BtVsB
**FileSplitterFetch.java *XuzTGa"
*/ 9Wn0YIc
package NetFox; VM`."un]
f63q
KtE`L4tW6
import java.io.*; C{-pVuhK+
import java.net.*; 3@PVUJ0B|
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q$P"o].EK
public class FileSplitterFetch extends Thread { _U %B1s3y
@z.!Dby
t{9Ph]e
String sURL; //File URL r%4:,{HF
long nStartPos; //File Snippet Start Position "P~>AXcq
long nEndPos; //File Snippet End Position CAO$Zt
int nThreadID; //Thread's ID % |V:F.f
boolean bDownOver = false; //Downing is over 6._):[_2
boolean bStop = false; //Stop identical .jU9{;[
FileAccessI fileAccessI = null; //File Access interface bmLNR
tq[C"| dH
i2DR}%U
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _>.%X45xi
{ eYFCf;
this.sURL = sURL; r\zK>GVm_
this.nStartPos = nStart; We|*s2!
this.nEndPos = nEnd; ^H'#*b0u
nThreadID = id; K^+B"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q5ux**(Wr
} (@ Bw@9
9Bn dbSi
7">.{ @S
public void run() Rp#SqRy`
{ =g ]C9'I3
while(nStartPos < nEndPos && !bStop) QnqX/vnR
{ ,=FYf|Z
%2.T1X%!
Y*6*;0Kx
try{ *T3"U|0_y
URL url = new URL(sURL); &nq[Vy0kO4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "F^EfpcJ{9
httpConnection.setRequestProperty("User-Agent","NetFox"); S$Wd}2>
String sProperty = "bytes="+nStartPos+"-"; .s+e hZ
httpConnection.setRequestProperty("RANGE",sProperty); KvgZx(.
Utility.log(sProperty); Aq-v3$XL
DE[y&]/C{
pP .
InputStream input = httpConnection.getInputStream(); -M4#dHR_!
//logResponseHead(httpConnection); E?-K_p
Z7 @#0;g{
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byte[] b = new byte[1024]; #Xc~3rg9
int nRead; }v:h EMO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uBM1;9h
{ wGB'c's*
nStartPos += fileAccessI.write(b,0,nRead); WrV|<%EQh
//if(nThreadID == 1) )S]c'}^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XH/|jE.9^|
} Gfvz%%>l
+1rJ;G
8w\&QX
Utility.log("Thread " + nThreadID + " is over!"); ,PB?pp8C}
bDownOver = true; @`T6\ 1
//nPos = fileAccessI.write (b,0,nRead); 4#o` -vcW
} /a,q4tD@
catch(Exception e){e.printStackTrace ();} ,Vogo5~X
} (wTg aV1
} R75sK(oS
54k Dez
>+1bTt/-F
//打印回应的头信息 + 7Z%N9
public void logResponseHead(HttpURLConnection con) )TLDNpH?J
{ uJ%ql5XDV
for(int i=1;;i++) =Ij;I~
{ Uc/%4Gx
String header=con.getHeaderFieldKey(i); |i|O9^*%
if(header!=null) I?1^\s#L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2Bx\nLf/ K
Utility.log(header+" : "+con.getHeaderField(header)); 4"GY0) Q
else J9o]$.e
break; 'rSM6j
} F:n7yey
} 3o1j l2n
(h E^<jNR
v"^G9u
public void splitterStop() #e=[W))
{ p}h)WjC
bStop = true; :/u EPki
} #jnb6v=5v
cc@y
TG!sck4/-Q
} n|8fdiK#}
/m%;wH|6%
Qml<JF
/* j_k!9"bt
**FileAccess.java VlKWWQj
*//文件访问(定位，写) O)&V}hU*
package NetFox; NpSS/rd $
import java.io.*; [z/OY&kF
EayZ*e]
W&*0F~
public class FileAccessI implements Serializable{ ZM\Z2L]n
WzF/wzR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 iZ&CE5+
RandomAccessFile oSavedFile; u-8,9
long nPos; tYVmB:l
pJV<#<#Z
;0 ,-ywK
public FileAccessI() throws IOException emTqbO
{ Qv#]T,
this("",0); BYRf MtT@+
} SI-s:%O
M-eX>}CDm
-2f_e3jF
public FileAccessI(String sName,long nPos) throws IOException Lb(=:Z!{
{ B%[Yu3gBo
oSavedFile = new RandomAccessFile(sName,"rw"); 1X]?-+',.
this.nPos = nPos; cZA l.}/
oSavedFile.seek(nPos); }s? 9Hnqa
} c!b4Y4eJ
.|!Kv+yD
G/b $cO}
public synchronized int write(byte[] b,int nStart,int nLen) Uh{|@D
{ @?TOg{:
int n = -1; {ymD.vf=9+
try{ K;Fy&p^d
oSavedFile.write(b,nStart,nLen); L)kwMk
n = nLen; :GK]"sNC
} G{)2f&<
catch(IOException e) l1nrJm8
{ bIR7g(PJ.b
e.printStackTrace (); Rkgpa/te"
} FK<1SOE
r"c<15g2'
=5J}CPKbZI
return n; ~~z}yCl
} `i;f
<8~bb-U$
M/T ll]\|
} BVU>M*k
q9|'!m5K
Y$ZZ0m
/* ("?V|
**SiteInfoBean.java &Yb!j
*/ O(#DaFJv
package NetFox; icH\(
'Y`or14E
DY1UP(y
public class SiteInfoBean { D&#wn.0|E
'b~,/lZd
,:;ZzHzR0
private String sSiteURL; //Site's URL ?`8jn$W^
private String sFilePath; //Saved File's Path f<?v.5($
private String sFileName; //Saved File's Name MDAJ p>o
private int nSplitter; //Count of Splited Downloading File ,#m:U5#h
{W,&jC
*d b,N'rK
public SiteInfoBean() ].w~FUa
{//nSplitter的缺省值为5 >8PGyc*9
//default value of nSplitter is 5 &#_c,c;
this("","","",5); ^zn&"@
} J#ujIe
QY|Rz(;m
hT go
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B)*?H=f/
{ B:;$5PUTc
sSiteURL= sURL; NCL!|
sFilePath = sPath; JS$ojL^
sFileName = sName; Cl&YN}t5
this.nSplitter = nSpiltter; 2!QQypQ
/-s-W<S[
ZW7z[,tk<.
} nHyqfd<V>
4h~CDy%_
ip8%9fG\>
public String getSSiteURL() fRh}n ^X
{ ZD~ra7
return sSiteURL; {9B"'65o
} :8=7)cW
gjFpM.D-.
0i[v,eS
public void setSSiteURL(String value) y!eT>4Oyg
{ ;8m)a
sSiteURL = value; $-n_$jLY
} *#B"%;Ln
D ~NWP%H
_9z+xl
public String getSFilePath() M:%Ll3
{ k-$J #
return sFilePath; .j`8E^7<
} lH>6;sE
\>e>J\t:
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public void setSFilePath(String value) >yr3C
{ v3]~*\!5
sFilePath = value; )umW-A
} z_:r&UP`"
1<wolTf
WZ ,t~TN
public String getSFileName() 'V*8'?
{ SqT+rvTh
return sFileName; 83:qIfF
} 9`DY6qfly
z9^_5la#
N<|-b0#Z6
public void setSFileName(String value) \LDcIK=
{ }-paGM@'Nd
sFileName = value; Jl89}Sf
} h>"Z=y
q<A,S8'm
7`K)7
public int getNSplitter() +Z%8X!Q
{ \J^xpR_0u
return nSplitter; KnYHjJa
} 9!Vp-bo
%(kf#[zQ
Q9 RCN<!
public void setNSplitter(int nCount) XOJ@-^BX
{ H3qL&xL
nSplitter = nCount; -!ERe@k(
} bl;v^HR0)
} IR*:i{
~sc@49p
w3peG^4D_
/* c#(&\g2H
**Utility.java $a+)v#?,
*/ ~7&O[
package NetFox; 69/qH_Y
hdee]qLS
k3t2{=&'&x
public class Utility { ]lzOz<0q
>.#tNFAs
.Dg'MMBM
public Utility() 9:6d,^X
{ +v'n[xa1v
,=p.Cx'PR
%uhhQ<zs%
} ,<?M/'4}G
jRIm_)
//线程睡眠 Z'z~40Bda
public static void sleep(int nSecond) vR"<:r47?
{ {p@uj_pS
try{ Li\BRlebR{
Thread.sleep(nSecond); s *1%I$=@
} ZI#Xh5
catch(Exception e) jj 9eFB
{ ihdtq
e.printStackTrace (); yw)Ztg)
} !4G<&hvb
} CDM==Xa*
OT5'cl
//日志 g8_IZ(%:
public static void log(String sMsg) kpN'H_ .
{ o<-+y\J8K
System.err.println(sMsg); wc'K=;c
} VCvqiHn
;"/ "
F-n1J?4b
public static void log(int sMsg) QP e}rQnm
{ M^^u{);q
System.err.println(sMsg); cAc i2e
} ]jzINaMav
} VSkx;P
?iBHJ{
1xo<V5
/* =>CrZ23B"
**TestMethod.java %j=,c{`Q
*/ 1v&!`^G99j
package NetFox; :8aIj_qds
`'[ 7M
cZ7b$MZ%9
public class TestMethod { &7X0 ;<
O"mU#3?
VMW?[j
public TestMethod() dR_hPBn/@
{ ///xx/weblogic60b2_win.exe <u"#Jw/VP
try{ OX4+1@$tk
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d}',Bl+u{$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +* )Qi)
SiteFileFetch fileFetch = new SiteFileFetch(bean); R#bg{|
fileFetch.start(); $hO8 S=
} <96ih$5D1
catch(Exception e){e.printStackTrace ();} 0r=Lilu{q
^ :Q |,oy
ki^[~JS>'
} N[ArwV2O
Z-H Kdv!d
^LT9t2
public static void main(String[] args) m=fmf(
{ Y@u{73H
new TestMethod(); gpr];lgS
} a+mq=K
} '7'cKp
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