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)); 'n4$dv%q
} -"MB(`
for(int i=0;i<nEndPos.length-1;i++) }0z]sYI
{ t}q\.
nEndPos = nStartPos[i+1]; 9L9+zs3k
} On4tK\l@
nEndPos[nEndPos.length-1] = nFileLength; TIre,s)_
} 2u?k;"]V
} eY#_!{*Wn
X6<%SJC
(,!G$~Sy
//启动子线程 vv5 uU8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; OX[pK_:`l
for(int i=0;i<nStartPos.length;i++) $~FnBD%|{
{ "-aCF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pGdo:L?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ( !=^(Nd
nStartPos,nEndPos,i); z}&JapJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MclW!CmJ
fileSplitterFetch.start(); $PE{}`#g
} pZaOd;t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nb,+!)+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %AnqT|\#,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1aBQ.-E-
nEndPos = " + nFileLength); "[tb-$ER
// fileSplitterFetch[nPos.length-1].start(); &D*22R4{CX
%1^E;n
0\2#(^
//等待子线程结束 IMtfi(Y%F
//int count = 0; "D1u2>(
//是否结束while循环 i]M:ntB"
boolean breakWhile = false; * j]"I=D
2GC{+*
9qXKHro
while(!bStop) }Z Nyd
{ ]p5]n*0X
write_nPos(); h1+lVAQbT
Utility.sleep(500); E[kf%\
breakWhile = true; (Y>|P
pRrokYM d
wseb]=U
for(int i=0;i<nStartPos.length;i++) k1HVvMD<
{ dD.;P=AP
if(!fileSplitterFetch.bDownOver) "Q<
{ E\lel4ai
breakWhile = false; b]cnTR2E
break; Z/~7N9?m(
} cH>3|B*y
} YR/%0^M'0
if(breakWhile) 6h%_\I.Z[[
break; /_.1f|{B
?f'iS#XL
mX&!/U
//count++; vS'l@`Eg]
//if(count>4) t`oH7)nut
// siteStop(); q@0g KC&U
} *j"u~ NF
FQW{c3%qZ
*p Q'w
System.err.println("文件下载结束！"); Vnvfu!>(
} vE<z0l
catch(Exception e){e.printStackTrace ();} GZCXm+
} 0V[`zOO(o
#$;i 4a
ll8Zo+-[
//获得文件长度 L$Yg*]\
public long getFileSize() CS|al(?~
{ %|\Af>o4d
int nFileLength = -1; |p\vH#6y+
try{ O\&-3#e
URL url = new URL(siteInfoBean.getSSiteURL()); ' zz^!@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %Z]c[V.
httpConnection.setRequestProperty("User-Agent","NetFox"); b"7L ;J5|
PRQEk.C
6#za\[
int responseCode=httpConnection.getResponseCode(); yHNx,ra
if(responseCode>=400) )g ; !IL
{ o`+$h:zm@
processErrorCode(responseCode); _KZ&/
return -2; //-2 represent access is error wJ Qm7n-+
} h5^qo ^;g7
FBGe s[,
k=M_2T'
String sHeader; QuWWa|g^.
lNs;-`I~
>pRC$'Usx
for(int i=1;;i++) f<;w1sM\
{ -lqsFaW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {;-wXzv`
//Utility.log(in.readLine()); >^N{
sHeader=httpConnection.getHeaderFieldKey(i); &8xwR
if(sHeader!=null) 3<R8_p
{ lGZf_X)gA^
if(sHeader.equals("Content-Length")) V(c>1xLlz
{ =%Z5"];
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b<E+5;u
break; Z;M th#
} c]]e(
} r~q3nIe/,
else $LOwuvu>
break; AJ"a
} KMll8X
} }|u>b!7_.
catch(IOException e){e.printStackTrace ();} vp|'Yy(9z
catch(Exception e){e.printStackTrace ();} h#JX$9
67D{^K"KT
Ahf71YP
Utility.log(nFileLength); >_'0 s
I3,0vnE@
rm?C_
return nFileLength; UVlh7wjg
} %yPjPUHy
Jk>!I\
G<:gNWXd\
//保存下载信息（文件指针位置） `)WC|=w2
private void write_nPos() M7gb3gw6
{ *F;W 1TF
try{ f[fH1cu&`
output = new DataOutputStream(new FileOutputStream(tmpFile)); Kv~'*A)d
output.writeInt(nStartPos.length); Ls6C*<8
for(int i=0;i<nStartPos.length;i++) ;>*Pwz`~jT
{ ,Z$!:U
// output.writeLong(nPos); Y5z5LG4
output.writeLong(fileSplitterFetch.nStartPos); /mG-g%gE
output.writeLong(fileSplitterFetch.nEndPos); u?7^+z
} G<M9 6V
output.close(); u8r<B4k
} B]#^&89wG)
catch(IOException e){e.printStackTrace ();} F_d>@-<
catch(Exception e){e.printStackTrace ();} WG]`Sy
} q{CD:I:-
iBh.&K{j
AkAQ%)6qV
//读取保存的下载信息（文件指针位置） u2 t=*<X
private void read_nPos() RaC8Sq7hW
{ *4OB 88$
try{ h$l`)AH^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T%]@R4z#q
int nCount = input.readInt(); L}=t"y
nStartPos = new long[nCount]; 6`WI S4
nEndPos = new long[nCount]; Mi)h<lY
for(int i=0;i<nStartPos.length;i++) BT^HlW<
{ y&L Lx[8^
nStartPos = input.readLong(); Fk`|?pQm
nEndPos = input.readLong(); a3J' c
} `MC5_SG 1
input.close(); 3<O=,F
} jp880}
catch(IOException e){e.printStackTrace ();} Rrw6\iO
catch(Exception e){e.printStackTrace ();} 8DkZ@}
} o3cE.YUF
PS$g*x
0iI|eE o
private void processErrorCode(int nErrorCode) M3!4,_!~
{ 'l $ViNq;
System.err.println("Error Code : " + nErrorCode); '37 <+N
} 'OI(MuSn
UK5u"@T
aNUMF
//停止文件下载 h{T{3
public void siteStop() Vl/fkd,Z
{ 3FG'A[x3O
bStop = true; hdDL92JVg
for(int i=0;i<nStartPos.length;i++) V;d<S@$
fileSplitterFetch.splitterStop(); Y?AvcY.
\ 0/m$V.
3?Fe(!@
} -unQ4G
} %m##i
//负责部分文件的抓取 $6]1T>
**FileSplitterFetch.java _0o65?F
*/ [L=M=;{4
package NetFox; @k9n0Qe|F
z:oi@q
n{(,r'
import java.io.*; #'4Psz
import java.net.*; !.{"Ttn;s
7QdboEa
_'Rg7zHTp-
public class FileSplitterFetch extends Thread { -ND1+`yD
-_BX\iP{
cq~~a(IS
String sURL; //File URL 2oo\SmO]
long nStartPos; //File Snippet Start Position >02p,W6S>
long nEndPos; //File Snippet End Position yp]z@SYA@
int nThreadID; //Thread's ID J"K(nKXO_?
boolean bDownOver = false; //Downing is over U>0bgL
boolean bStop = false; //Stop identical y*!8[wASHq
FileAccessI fileAccessI = null; //File Access interface l p|`n
qNWSDZQ
5a|{ytP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S5\KI+;PW
{ f h:wmc'
this.sURL = sURL; nh? JiH {
this.nStartPos = nStart; X*M2 O%g`L
this.nEndPos = nEnd; {Ga=;0
nThreadID = id; nd"$gi
fileAccessI = new FileAccessI(sName,nStartPos);//定位 VNwOD-b/]
} P6A##z
qwq5yt?
Fg0!2MKq*
public void run() d^8n
{ NInZ~4:
while(nStartPos < nEndPos && !bStop) :xk+`` T
{ r-No\u_
piFZu/~Gq\
gF:|j(
try{ U+[h^M$U
URL url = new URL(sURL); j>G|Xv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5|Oj\L{
httpConnection.setRequestProperty("User-Agent","NetFox"); f^lhdZ\
String sProperty = "bytes="+nStartPos+"-"; ~9#'s'
httpConnection.setRequestProperty("RANGE",sProperty); q4g)/x%nc
Utility.log(sProperty); K%UjPzPWw
XB]>Z)
6Zx5^f(qd
InputStream input = httpConnection.getInputStream(); dEkAUH
//logResponseHead(httpConnection); #u3E{NB
HGF&'@dn
vXg^K}a#
byte[] b = new byte[1024]; vj|#M/3>
int nRead; qL5~Wr m-W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3`;1;T2$B
{ (9b%'@A@m
nStartPos += fileAccessI.write(b,0,nRead); T^q^JOC4
//if(nThreadID == 1) c4.2o<(Xt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {s{+MbD
} )hC3'B/[Y
e/x6{~ju^N
T.W^L'L`
Utility.log("Thread " + nThreadID + " is over!"); UG3}|\.u
bDownOver = true; ^].U?t.n)
//nPos = fileAccessI.write (b,0,nRead); D^6Q`o
} jp|*kBDq\
catch(Exception e){e.printStackTrace ();} 4I#@xm8)
} qMw_`dC
} In8{7&iVO
9CAu0N5<
:KqSMuKR
//打印回应的头信息 <sSH^J4QqX
public void logResponseHead(HttpURLConnection con) Tj}%G
{ .>S1do+
for(int i=1;;i++) J>"qeR /
{ + Y!:@d
String header=con.getHeaderFieldKey(i); s^m`qi(H
if(header!=null) !x!1H5"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5s@xpWVot
Utility.log(header+" : "+con.getHeaderField(header)); sRZ?Ilua6
else FL b
break; g_0| `Sm
} G @EEh.s9
} v`S ;.iD
r;p@T8k
o#WECs>
public void splitterStop() M(I%QD
{ 0sH~H[ap
bStop = true; smn~p/u
} MI-S}Qoe
6Hfv'X5E`Z
V+r&Z<&
} |T]&8Q)S
q=*bcDu
pfw`<*e'
/* /1_O5'5+v
**FileAccess.java wPq9`9 #
*//文件访问(定位，写) .hUlI3z9
package NetFox; ,3!TyQ\m'
import java.io.*; %Y,Ru)5}
8l'W[6
*3s-=.U~
public class FileAccessI implements Serializable{ VVcli*
gyegdky3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ryqu2>(
RandomAccessFile oSavedFile; qJ2Z5
long nPos; X_!km-{
h50]%tp\
w03Ur4>T
public FileAccessI() throws IOException Tu}EAr
{ =\)zb'\=d
this("",0); };P=|t(r
} rxy5Nrue
b-@9Xjv
1.8"N&s
public FileAccessI(String sName,long nPos) throws IOException %8Y+Df;ax
{ 69:-c@L0
oSavedFile = new RandomAccessFile(sName,"rw"); ~g#/q~UE
this.nPos = nPos; suWO:]FR
oSavedFile.seek(nPos); fY78
} HSU?4=Q
SfY9PNck\
%FqQ+0^
public synchronized int write(byte[] b,int nStart,int nLen) t"J{qfNs
{ H4YA
int n = -1; >X:!Y[N
try{ grkA2%N
oSavedFile.write(b,nStart,nLen); z"7X.*]
n = nLen; &IRM<A!8
} 8gt*`]I
catch(IOException e) R/E6n &R
{ ZpBP#Y*
e.printStackTrace (); %`lJAW[
} DaGny0|BB
_.]mES|
pAA)?/&oKV
return n; KC(z TY
} .EjR<UU
)^6Os2
{;u+?uY
} (w(k*b/
AkO);4A;Jd
:Zob"*T
/* 6<5:m:KE
**SiteInfoBean.java ln,9v
*/ X+,0;% p
package NetFox; v&]yzl
~>0H k}Hv
i tk/1
public class SiteInfoBean { ?0JNaf
[^/a`Kda8
2_M+o]Z^
private String sSiteURL; //Site's URL }o[<1+W(.
private String sFilePath; //Saved File's Path q j9q
private String sFileName; //Saved File's Name 61gyx6v
private int nSplitter; //Count of Splited Downloading File DYgB_Iak
uT<<G)v)
9^Web~yi#
public SiteInfoBean() MI:%Eq
{//nSplitter的缺省值为5 C#)T$wl[E
//default value of nSplitter is 5 yn<J>e
this("","","",5); j]R[;8g
} TVSCjI
Ux=B*m1@{
a+~b3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gnxD'1_
{ r[GH#vF;7
sSiteURL= sURL; :kwDa a
sFilePath = sPath; IQ-l%x[fue
sFileName = sName; #O8=M(- V
this.nSplitter = nSpiltter; 15' fU!
9!Xp+<
Cp>y<C"
} }ALli0n`V)
=iDd{$
cc}#-HKR[
public String getSSiteURL() 9zCuVUcd$.
{ 1Qz@
return sSiteURL; D~M R)z_p~
} T:|p[Xbo
hy$VG%b;#
f4+wP/n&
public void setSSiteURL(String value) ?gvu E1
{ aX|(%1r
sSiteURL = value; (FgX9SV]p9
} MpJ<.|h
q6>}
aU[!*n 4Ux
public String getSFilePath() rwgj]
{ ^L7!lzyo
return sFilePath; &1`Y&x:p
} H/;AlN|!
<$25kb R5K
e+VE FWz
public void setSFilePath(String value) h9iQn<lp4.
{ 5tZ0zr
sFilePath = value; \$ss
} 8_S| 8RW(
.j**>&7L
elpTak@
public String getSFileName() 3=} P l,
{ {{gt>"D,
return sFileName; T-/3 A%v
} FCKyKn
bz~aj}"`
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public void setSFileName(String value) y}|E)
{ aD_7^8>
sFileName = value; a1%}Ee
} 8IBr#+0
ib!TXWq
A:yql`&s
public int getNSplitter() (pd~ 2!;C
{ &%qDi_UD
return nSplitter; Tm7LaM
} MEp{&#v|1
x7`+T1IJ
9$C?)XKXB
public void setNSplitter(int nCount) X')l04P@%
{ 8Djki]
nSplitter = nCount; DQ[7p(
} d&f!\n_~
} VEn3b
vX}w_Jj>
<8Nr;96IA
/* 8pftc)k
**Utility.java _VmXs&4
*/ gG}H5uN
package NetFox; M7 kWJ
a)Pr&9I
;Bzx}7A
public class Utility { }&2,!;"">3
6iF&!Fd>J
ki/Cpfq40*
public Utility() O|^J;fS:
{ >kmgYWG
eO*s,*
RO%M9LISI
} !y'>sAf
Ht\2 IP
//线程睡眠 .]JIo&>5
public static void sleep(int nSecond) T{"Ur:p
{ n~}[/ly
try{ k)X\z@I'
Thread.sleep(nSecond); U,61 3G
} nKnrh]hX
catch(Exception e) eMmNQRmH
{ #d/T7c#
e.printStackTrace (); ~UNha/nt
} "+wkruC
} S?C.:
iF837ng5
//日志 op9vz[o#4
public static void log(String sMsg) .QwB7+V4
{ I.T?A9Z
System.err.println(sMsg); v-q-CI?B#
} z9g6%RbwX
fiD,HGx i
B$x@I\(M
public static void log(int sMsg) i'"#{4I
{ ZZTf/s*
System.err.println(sMsg); ]FIIs58IM
} ~K<h~TNP
} ,r]H+vWS
g;6/P2w
B, H9EX
/* D_~;!^
**TestMethod.java CmBgay
*/ >P\eHR,{-
package NetFox; c_M[>#`
jWi~Q o+
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public class TestMethod { &NoA, `|7
WWZ<[[ >
(FaYagD
public TestMethod() =s]2?m
{ ///xx/weblogic60b2_win.exe bM:4i1Z
try{ {#4a}:3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H>;,r,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7Hgn/b[?b
SiteFileFetch fileFetch = new SiteFileFetch(bean); rwP)TJh"
fileFetch.start(); [)GRP
} -$0}rfX
catch(Exception e){e.printStackTrace ();} ?~t5>PEonv
?E|=eO"I1
!X~NL+
} 7iwck.*
dh [kx
l5&5VC)
public static void main(String[] args) fR'!p: ~
{ bn8maYUZ
new TestMethod(); |)Dm.)/0)
} i$@xb_
} D6&P9e_5
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