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)); #Nt?4T<
} C:n55BE9
for(int i=0;i<nEndPos.length-1;i++) Q(-:)3g[aL
{ Vwp fkD`
nEndPos = nStartPos[i+1]; [@OXvdTV
} R qS2Qo]
nEndPos[nEndPos.length-1] = nFileLength; %@Nuzdp
} fiSc\C~
} cvpcadN[
E3#}:6m
a;eV&~
//启动子线程 Kc=&jCn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~y+QL{P4~
for(int i=0;i<nStartPos.length;i++) %C%~f{4
{ uj$b/I>.'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !2WRxM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8>Hnv]p
nStartPos,nEndPos,i); d,|W
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xp%,@]p
fileSplitterFetch.start(); mnM#NT5]
} 8t!/Op?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )TxAhaz+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~Dw.3P:-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5taYm'
nEndPos = " + nFileLength); pHlw&8(f"
// fileSplitterFetch[nPos.length-1].start(); Nhv~f0
Akf?BB3bC
J7BfH,o
//等待子线程结束 Ij hC@5qk
//int count = 0; DCv~^
//是否结束while循环 3&kHAXzM
boolean breakWhile = false; $-m`LF@
6elmLDMni\
p]uwGWDI
while(!bStop) ir<HC 'D[
{ ]<mXf~zg
write_nPos(); BlQu9{=n
Utility.sleep(500); tWYKW3~]
breakWhile = true; v;X'4/M
87zsV/
-Cwx %
for(int i=0;i<nStartPos.length;i++) ZYoWz(
{ q&0Jl
if(!fileSplitterFetch.bDownOver) /#M|)V*wn
{ *P&ZE
breakWhile = false; \D] N*
break; _NAKVzo-
} ]R/VE"-
} 6X5`npf
if(breakWhile) -"iGcVV
break; 5QU7!jbI
+2=N#LM
a!}.l< )
//count++; wn[q?|1
//if(count>4) Q_'3}:4
// siteStop(); zFh JLH*C
} :\1:n
dI<s)!
Mt)`hR+2
System.err.println("文件下载结束！"); m98j`t
} c6cGl]FL
catch(Exception e){e.printStackTrace ();} MV5'&" ,oB
} s{#ZRmc2B
|:n4t6
0n+Wv@/
//获得文件长度 U@dztX@u
public long getFileSize() CF3Z`xD
{ }wrZP}zM>
int nFileLength = -1; Q*mzfsgr
try{ ;JMd(\+-
URL url = new URL(siteInfoBean.getSSiteURL()); wE:hl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ig^9lM'
httpConnection.setRequestProperty("User-Agent","NetFox"); $Ml/=\EHOg
QIVpO /@
Fn*clx<
int responseCode=httpConnection.getResponseCode(); 't \:@-tQ
if(responseCode>=400) ,9gyHQ~
{ TOV531
processErrorCode(responseCode); {~ ZSqd
return -2; //-2 represent access is error ,JyE7h2%i
} Rm 1obP
1 ry:Z2
09`5<9/
String sHeader; DYJ@>8
&GcWv+p
TjGe8L:
for(int i=1;;i++) ?V%x94B
{ EO$_]0yI;_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $;Lb|~
//Utility.log(in.readLine()); 1SeDrzLA
sHeader=httpConnection.getHeaderFieldKey(i); (UPkb$Qc
if(sHeader!=null) ?U:?o_w
{ u^SXg dj
if(sHeader.equals("Content-Length")) "|V{@)!t
{ _, /m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )nyud$9w'
break; $A)i}M;uK
} %>}6>nT#
} $}r*WZ
else g PogV(V
break; ~hPp)-A
} 8 ZD1}58U4
} g![]R-$
catch(IOException e){e.printStackTrace ();} AxLnF(eG
catch(Exception e){e.printStackTrace ();} 4;WeB
{4Cn/}7Ly^
\k_0wt2x1
Utility.log(nFileLength); 5FcKY_
gUzCDB^.:
qlmz@kTb
return nFileLength; pXPwn(
} J6/Mm7R
#bgW{&_y
vULlAQG
//保存下载信息（文件指针位置） IwhZzw w
private void write_nPos() S',i
{ w35r\x +
try{ {X<mr~
output = new DataOutputStream(new FileOutputStream(tmpFile)); &Al9%W
output.writeInt(nStartPos.length); q}*"0r
for(int i=0;i<nStartPos.length;i++) !tBNA
{ /Za'L#=R
// output.writeLong(nPos); 5fPYtVm
output.writeLong(fileSplitterFetch.nStartPos); 12v5*G[X
output.writeLong(fileSplitterFetch.nEndPos); 2KMLpO&De
} |5S/h{gq
output.close(); =XsdR?C
} m{Jo'*%8f
catch(IOException e){e.printStackTrace ();} nw[DI%Tp
catch(Exception e){e.printStackTrace ();} RX:wt
} LS@[O])$'
9B")/Hz_
IO~d.Ra
//读取保存的下载信息（文件指针位置） K <7#;
private void read_nPos() \]=qGMwFs
{ saQA:W;
try{ p"f=[awp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -q\5)nY
int nCount = input.readInt(); 4Waot
nStartPos = new long[nCount]; p*)RP2
nEndPos = new long[nCount]; !/, 6+2Ru
for(int i=0;i<nStartPos.length;i++) N r5 aU6]
{ eYBo*
nStartPos = input.readLong(); [RG&1~
nEndPos = input.readLong(); [,)yc/{*
} De,4r(5
input.close(); YP{)jAK
} @54,I
catch(IOException e){e.printStackTrace ();} b}4k-hZL
catch(Exception e){e.printStackTrace ();} Hi#'h
} 2GQq(_
ysD@yM,
NKB,D$!~&
private void processErrorCode(int nErrorCode) "ut:\%39.
{ 68?oV)fE
System.err.println("Error Code : " + nErrorCode); 4a]m=]Hm
} 4&;.>{:;
}c(".v#
zlzr;7m
//停止文件下载 N8|=K_;&
public void siteStop() hM\<1D CKG
{ zq-"jpZG
bStop = true; {^gbS
for(int i=0;i<nStartPos.length;i++) AEaT
fileSplitterFetch.splitterStop(); 2)]C'
x"h0Fe?J
:" Q!Q@>
} dk~h
} 0mo^I==J1
//负责部分文件的抓取 iaO;i1K5U
**FileSplitterFetch.java uP/PVoKQ
*/ ! )$ PD@
package NetFox; V0+D{|thh6
f)hs>F
flp<QT
import java.io.*; gv$6\1
import java.net.*; V_jVVy30Ji
aCzdYv\}&
&RP!9{F<
public class FileSplitterFetch extends Thread { <y1V2Np
LcCb[r
4qo4g+
String sURL; //File URL 9'F-D
long nStartPos; //File Snippet Start Position (yQ]n91Q,
long nEndPos; //File Snippet End Position 7qSlqA<Hs
int nThreadID; //Thread's ID Dt?O_Bdv[
boolean bDownOver = false; //Downing is over 6#VG,'e3
boolean bStop = false; //Stop identical Okm&b g
FileAccessI fileAccessI = null; //File Access interface QA7SQcd,
e&Z}struE
_KiaeVE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException INSI$tA~
{ -\:#z4Tc
this.sURL = sURL; 33x3zEUt6
this.nStartPos = nStart; HpXMPHd
this.nEndPos = nEnd; Wh[+cH"M
nThreadID = id; H6?ZE
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7cin?Z1
} b3}928!D-@
@>f]0,"(
)\_xB_K\
public void run() yA_;\\
{ w#[Ul9=?6
while(nStartPos < nEndPos && !bStop) 1BQTvUAA
{ ?l#9ydi?
rm2"pfs
%98F>wl
try{ /!ZeMY:x
URL url = new URL(sURL); ,?i^i#Wqzg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YAnt}]u!"
httpConnection.setRequestProperty("User-Agent","NetFox"); M iIH&z
String sProperty = "bytes="+nStartPos+"-"; _.0c~\VA
httpConnection.setRequestProperty("RANGE",sProperty); 3n9$qr='
Utility.log(sProperty); EJY[M
E 5}T_~-{
@-~YQ@08`
InputStream input = httpConnection.getInputStream(); *0M#{HQ
//logResponseHead(httpConnection); 8[5%l7's
D.xN_NK"
_ b}\h,Ky
byte[] b = new byte[1024]; 9PhdoREb
int nRead; @<Au|l`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ls#pe
{ \W;~[-"#
nStartPos += fileAccessI.write(b,0,nRead); \V`O-wcJ]S
//if(nThreadID == 1) ?TLEZlB2"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0(#HMBE8
} pHFlO!#]|
KY/}jJW
w~M5)b
Utility.log("Thread " + nThreadID + " is over!"); J'^s5hxn+0
bDownOver = true; 5} |O
//nPos = fileAccessI.write (b,0,nRead); 2{c ;ELq
} %~P]x7%|
catch(Exception e){e.printStackTrace ();} >|SB]'C|
} .E!7}O6
} )a,-Hc:Vz
XPXC7_fV
!OM9aITv[
//打印回应的头信息 x^_Wfkch]
public void logResponseHead(HttpURLConnection con) {OP-9P=p
{ ie^:PcU
for(int i=1;;i++) ncJ}h\:Sk
{ At%g^
String header=con.getHeaderFieldKey(i); U,)Ngnd
if(header!=null) Taxi79cH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k\_>/)g
Utility.log(header+" : "+con.getHeaderField(header)); W]5kM~Q@
else 5)V]qV$
break; XG<J'3
} ` _()R`=
} q:#,b0|bv
-_'M *-
$1oU^VY
public void splitterStop() ]+)z}lr8 C
{ N%6jZmKip
bStop = true; %*OKhrM
} E*IkI))X0
Vi`+2%4
V S2p"0$3D
} ,HS\(Z
1YR;dn
^ef:cS$;
/* ]7zDdI|
**FileAccess.java &q1(v3cOO
*//文件访问(定位，写) cRz7.9-<
package NetFox; 5R4h9D5
import java.io.*; $=iz&{9
UV)[a%/SB&
(rFY8oHD
public class FileAccessI implements Serializable{ CU6rw+Vax
2N)=fBF%-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %Z&[wU~
RandomAccessFile oSavedFile; k<=.1cFh
long nPos; :BCjt@K}
ttLChL
R+lKQAyC0=
public FileAccessI() throws IOException hU5[k/ q
{ VZYdCZ&l7
this("",0); .{HU1/!
} -"Lia!Q]M
n?@3R#4D3
'1ff|c!x9
public FileAccessI(String sName,long nPos) throws IOException fMwJwMT8
{ 8kAG EiC
oSavedFile = new RandomAccessFile(sName,"rw"); gm8L5c V
this.nPos = nPos; &PD4+%!
oSavedFile.seek(nPos); IvetQ+
} gd.P%KC!g
@z$V(}(O^
)!3XM
public synchronized int write(byte[] b,int nStart,int nLen) Cst\_j
{ Bcrd}'no
int n = -1; ^Ot+,l)
try{ 7u,56V?X
oSavedFile.write(b,nStart,nLen); 6VolTy@(x
n = nLen; cg7NtY
} JoKD6Q1D
catch(IOException e) Ts0.Ck
{ wke$
e.printStackTrace (); :::"C"Ge
} wED~^[]f
?)Z~H,Q(z
R_uA!MoLs
return n; {~16j"
} {i~qm4+o
#93;V'b]
N_$ X4.7p
} CY)Wuv ^
~t<BZu
cG?RisSZ
/* 2{"Wa|o`
**SiteInfoBean.java h(d<':|
*/ zdyS"H}
package NetFox; [[JwHM8H&
^qiTO`lg
LB? evewu
public class SiteInfoBean { T'\lntN
{4CkF\
vb9G_Pfz
private String sSiteURL; //Site's URL "pdG%$
private String sFilePath; //Saved File's Path _zJY1cr
private String sFileName; //Saved File's Name "6 dC
private int nSplitter; //Count of Splited Downloading File rv;w`f
0Z2![n
Gi]Pwo${
public SiteInfoBean() p(Y'fd}
{//nSplitter的缺省值为5 PAH; +
//default value of nSplitter is 5 Niou=PI@
this("","","",5); (8@._
} SWO$#X /
&kXf)xc<~
RJnRbaC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2aW&d=!ZV
{ S`K8e^]
sSiteURL= sURL; =B*,S#r
sFilePath = sPath; J.?6a:#bU/
sFileName = sName; nEQw6q~je
this.nSplitter = nSpiltter; :uZcN
HkJ$r<J2
SR%h=`t
} }UHuFff,
ff?:_q+.N
65=i`!f
public String getSSiteURL() N#C,_ k
{ &Dqg<U
return sSiteURL; H~J#!3
} h<6@&yzp
/JtKn*?}:>
j9) Z'L
public void setSSiteURL(String value) ^=pn!lK;^
{ _tb)F"4V
sSiteURL = value; (O,|1
} +MGEO+
+aEE(u6%E@
pUYa1=
public String getSFilePath() MJ8z"SKnV
{ ZR6KE_
return sFilePath; &0K H00l
} ,;O+2TX
4punJg~1
;wp)E nF
public void setSFilePath(String value) >7@F4a
{ ,X+mXtg.
sFilePath = value; d.% Vm&3
} fJd!;ur)0
!R[o6V5T
cDxjD5E
public String getSFileName() PZf^r
{ jToA"udW/
return sFileName; (lwkg8WC
} -1:yqF.x
'S)}mG_
xdXt
public void setSFileName(String value) ,l#V eC
{ /"~CWNa
sFileName = value; i=o<\{iV:
} +[V?3Gdb
@;G}bYq^(I
Tr(w~et
public int getNSplitter() 3E+u)f lmB
{ :p=IZY
return nSplitter; |B;:Ald
} <S6|$7{1
(YGJw?]
|TkMrj0
public void setNSplitter(int nCount) FlrLXTx0
{ X@\rg}kP
nSplitter = nCount; x!tCK47Yq
} zo7Hm]W`
} rts@1JY[
s0E:hn:
&xj?MgdNL
/* ZxwI< T:&
**Utility.java = =cAL"Z
*/ 8qrE<RHU@
package NetFox; i?A4uyYwS
:jT1=PfL
U9y[b82
public class Utility { ](aXZ<,
DdN{=}A
0%cbno@1V
public Utility() <I&X[Sqp
{ ?Sh]m/WZd[
=xw) [
54-sb~]
} "/(J*)%{
|/Ggsfmby
//线程睡眠 (VI4kRj
public static void sleep(int nSecond) *A@~!@XE4
{ ';^VdR]fk
try{ dArg'Dc4
Thread.sleep(nSecond); v<ASkkh>
} DKPX_::
catch(Exception e) O< v0{z09*
{ l7ZqkGG]
e.printStackTrace (); ]KA|};>ow
} ^$FHI_
} AcwLs%'sx
f2`[skNj
//日志 dli?/U@hO
public static void log(String sMsg) :Z- =1b~
{ uv%T0JA/
System.err.println(sMsg); 7s4G|N[wR\
} %|I~8>m
N8@Fj!Zi
==RYf*d
public static void log(int sMsg) ~dkS-6q~Q
{ ?<ks^2D
System.err.println(sMsg); k^w!|%a[
} nVoL7ew+
} #e}Q|pF
$>hPB[[
`k+ci7;
/* `1=n H/E
**TestMethod.java H!y1&
*/ C?fd.2#U
package NetFox; [6`8^-}?
^a0{"|Lq
CCNrjaA
public class TestMethod { E].hoq7WiB
Bk_23ygO_
j_H9l,V
public TestMethod() )>QpR8 G-
{ ///xx/weblogic60b2_win.exe V8@VR`!'
try{ fZw/kjx@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p9 <XaJ}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ve49m%NQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); DI{VJ&n66
fileFetch.start(); E z?O gE{
} Iq]+O Q
catch(Exception e){e.printStackTrace ();} -y|>#`T/
)"/.2S;
v-B{7 ~=#Z
} <U%4$83$
U>H"N1
r7+"i9
public static void main(String[] args) F0t-b%w,
{ I<L
new TestMethod(); WWhAm{m
} K|%.mcs4
} H*51GxK
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