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)); 'k4E4OB
} cOPB2\,
for(int i=0;i<nEndPos.length-1;i++) "dI;
{ Sr%;fq
nEndPos = nStartPos[i+1]; ap{2$k ,
} O9g{+e`
nEndPos[nEndPos.length-1] = nFileLength; :%sXO
} FIbp"~
} i:u1s"3~
$6CwkM:
(s{RnD
//启动子线程 2'5]~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vq!_^F<
for(int i=0;i<nStartPos.length;i++) 7f~Sf
{ _L@2_#h!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *P#WDXRwd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?}m']4p
nStartPos,nEndPos,i); Q4*fc^?u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jq+A-T}@
fileSplitterFetch.start(); ,:`ND28V7
} JB>b`W9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A0fFv+RN3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (sQr X{~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bk)g;+@
nEndPos = " + nFileLength); 'sxNDnGg
// fileSplitterFetch[nPos.length-1].start(); {'AWZ(
;q:jl~
($LLl;1
//等待子线程结束 jaa"~5TO8
//int count = 0; 2KQoy;
//是否结束while循环 cZ<A0
boolean breakWhile = false; 6<'21
P1NJ^rX
wN2QK6Oc
while(!bStop) O)Y?=G)
{ gt/zpiKmV
write_nPos(); ;L,mBQB?0b
Utility.sleep(500); Y& F=t/U2
breakWhile = true; &`fhEN
{&"L~>/o
(I@rLvZr{
for(int i=0;i<nStartPos.length;i++) eQVZO>)P1+
{ iC*F
if(!fileSplitterFetch.bDownOver) [xT:]Pw}
{ EZYBeqv
breakWhile = false; P)uDLFp]
break; 8o/}}=m$
} 5r?m&28X
} !xwG%{_
if(breakWhile) ]XTu+T.aT
break; Z(9u<
[|lB5gi4t!
doB
//count++; 4&HXkRs:
//if(count>4) /l{&iLz[
// siteStop(); m~>Y{F2
} 3 E3qd'
_$p$")
j+^oz'q
System.err.println("文件下载结束！"); N |1>ooU[
} OKHX)"j\\
catch(Exception e){e.printStackTrace ();} ^::EikpF%
} P1zdK0TM
?\#N9+{W
IJJ%$%F/
//获得文件长度 F|&{Rt
public long getFileSize() k2xHH$+{#=
{ 7y`}PMn
int nFileLength = -1; cS.-7
try{ (4@lKKiU%H
URL url = new URL(siteInfoBean.getSSiteURL()); 5o/&T"]@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RID]pek
httpConnection.setRequestProperty("User-Agent","NetFox"); fl;s9:<
jA(>sz
zSE<"(a
int responseCode=httpConnection.getResponseCode(); .c#y%S
if(responseCode>=400) rS0DSGDq
{ VqE~c
processErrorCode(responseCode); < Z|Ep1W
return -2; //-2 represent access is error oxj3[</'k
} vm'5s]kdh
@w>zF/
WsFk:h'r
String sHeader; tV9LD>3
(Z}>1WRju
nkv(~ej(
for(int i=1;;i++) @vMA=v7a
{ QaGlR`Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9 C{;h
//Utility.log(in.readLine()); 4G@nZn
sHeader=httpConnection.getHeaderFieldKey(i); \j2;4O?`
if(sHeader!=null) hb/]8mR
{ X]loJoM9
if(sHeader.equals("Content-Length")) |ea~'N1
{ 7?v#'Ies
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2qi'g:qe
break; /cK%n4l.y
} SSBg?H'T
} JxjI]SF02
else ~O 3D[PNW~
break; xvNo(>
} f/kI|Z
} W- $a Y2
catch(IOException e){e.printStackTrace ();} 5/QRL\
catch(Exception e){e.printStackTrace ();} cE iu)2*e
SI_iI71
3M0+"l(X
Utility.log(nFileLength); ez3Z3t`
fZKt%m
Wy]^Ub gW
return nFileLength; ,&Wn [G<2
} rtQHWRUn
J4=_w
81%8{yn!$"
//保存下载信息（文件指针位置） =V97;kq+v
private void write_nPos() &ff&Y.q~
{ WhBpv(q}.
try{ ^2odr \
output = new DataOutputStream(new FileOutputStream(tmpFile)); H +bdsk
output.writeInt(nStartPos.length); Og%U
for(int i=0;i<nStartPos.length;i++) fnCItK~y
{ <e%F^#y_
// output.writeLong(nPos); J!ntXF
output.writeLong(fileSplitterFetch.nStartPos); f&4,?E;6%
output.writeLong(fileSplitterFetch.nEndPos); LzDI0a.
} L5IbExjV
output.close(); 65,(4Udz!
} J wmT/
catch(IOException e){e.printStackTrace ();} )U:2z-X&e
catch(Exception e){e.printStackTrace ();} /$"[k2 N
} QFPfIb/
O;HY%
L?Yoh<
//读取保存的下载信息（文件指针位置） N:VX!w
private void read_nPos() W YW|P2*
{ o$.e^XL
try{ r,(et
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); nsb4S{
int nCount = input.readInt(); I1U7.CT
nStartPos = new long[nCount]; @OV-KT[>
nEndPos = new long[nCount]; k;dXOn
for(int i=0;i<nStartPos.length;i++) z5Qs@dG
{ .7ayQp
nStartPos = input.readLong(); /q\_&@
nEndPos = input.readLong(); ~n!!jM:N
} M!M!Ni
input.close(); =\, qP
} f DgD@YCD
catch(IOException e){e.printStackTrace ();} %m{U& -(l@
catch(Exception e){e.printStackTrace ();} kJs^ z
} 5wC* ?>/
]>i~6!@
jx_4B%kzq
private void processErrorCode(int nErrorCode) jY!ZkQsVe
{ $mA5@O~C5\
System.err.println("Error Code : " + nErrorCode); IB9%QW"0
} T:asm1BC[
17g^ALs
1;eX&
//停止文件下载 pN[0YmY#
public void siteStop() IO.<q,pP!_
{ /DS?}I.*]
bStop = true; Wx)K*9
for(int i=0;i<nStartPos.length;i++) 4YU/uQm
fileSplitterFetch.splitterStop(); sTHq&(hLUG
PWgDFL?
smAC,-6]~
} ^a9 oKI9n
} ^ons:$0h
//负责部分文件的抓取 R@T6U:1
**FileSplitterFetch.java +:jT=V"X
*/ YJ7V`Np
package NetFox; !$XHQLqF2
ZC^C
}UyQ#U
import java.io.*; 3mt%!}S
import java.net.*; 6\dX
Md;/nJO~{
VU!w!GN]Y
public class FileSplitterFetch extends Thread { -[#n+`M
~bA,GfSn0
_.18z+
String sURL; //File URL SjcL#S($&Y
long nStartPos; //File Snippet Start Position BZ+-p5]-
long nEndPos; //File Snippet End Position w3*-^: ?j
int nThreadID; //Thread's ID R -elIp
boolean bDownOver = false; //Downing is over :_dICxaLZT
boolean bStop = false; //Stop identical K3$` Kv>I
FileAccessI fileAccessI = null; //File Access interface rE!1wc>L
MXAEX2xmme
&w~Xa( uu
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 73NZ:h%=
{ [!*xO?yCJ
this.sURL = sURL; EH9Hpo
this.nStartPos = nStart; ,qFA\cO*
this.nEndPos = nEnd; q@#BPu"\l
nThreadID = id; L0h G
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1-;?0en&0
} \x\.
uVU`tDzd:
K!8zwb=fq
public void run() Aa(<L$e!`
{ Ns~&sE:
while(nStartPos < nEndPos && !bStop) (RF>s.B<
{ !)H*r|*[
(7q^FtjA#
,I*X)(
try{ +$beo2x6
URL url = new URL(sURL); I ,FqN}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^o<[. )
httpConnection.setRequestProperty("User-Agent","NetFox"); s^|\9%WD
String sProperty = "bytes="+nStartPos+"-"; 99ASIC!
httpConnection.setRequestProperty("RANGE",sProperty); w^VSj%XH!
Utility.log(sProperty); whkJpK(
#+sF`qR,
0'ZYO.y
InputStream input = httpConnection.getInputStream(); mc@M,2@D
//logResponseHead(httpConnection); nX x=1*X
iK}v`xq
H*U`
byte[] b = new byte[1024]; ]O{_O&w
int nRead; NtZ6$o<Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,Q2N[Jwd$
{ Sni=gZK
nStartPos += fileAccessI.write(b,0,nRead); #3.)H9
//if(nThreadID == 1) 71iRG*O
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @&R1wr1>I5
} 1i?=JAFfM
m4**>!I
O2#S: ~h
Utility.log("Thread " + nThreadID + " is over!"); DzDj)7
bDownOver = true; 1$["79k
//nPos = fileAccessI.write (b,0,nRead); 23E0~O
} 5d 5t9+t
catch(Exception e){e.printStackTrace ();} O3_B<Em
} co]Gmg6p
} Va9q`XbyO
T^)plWw
Xem| o&
//打印回应的头信息 p{H0dj^|
public void logResponseHead(HttpURLConnection con) G,DOBA
{ "a(1s},
for(int i=1;;i++) S%+R#A1
{ t"YIq/08
String header=con.getHeaderFieldKey(i); d^aNR Lv
if(header!=null) Y+|PY? ~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %Dyh:h
Utility.log(header+" : "+con.getHeaderField(header)); Mvof%I
else NWISS
break; [ -12]3
} [h", D5
} *)%dXVf
&:8T$UV
GVObz?Z]SB
public void splitterStop() &:auB:b
{ 9t}xXk
bStop = true; 8eww7k^R
} G2@KI-
)5i*/I\
qc-C>Ra
} \dNhzd#
3:" &Z6t#
q%.bnF/Yd
/* 0^iJlR2
**FileAccess.java .;Z.F7{q
*//文件访问(定位，写) 5&%fkZ0
package NetFox; j];G*-iv{
import java.io.*; Kw*~W i
bA+[{
9RcM$[~
public class FileAccessI implements Serializable{ i@{*O@m
>nNl^ yqW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T{;=#rG<
RandomAccessFile oSavedFile; =+(Q.LmhC
long nPos; l'2H4W_+
y*|L:!
x~(y "^ph
public FileAccessI() throws IOException jNqVdP]d\
{ J(hA^;8:
this("",0); UC#"=Xd4
} <[5#c*A
u2,H ]-
E@]sq A
public FileAccessI(String sName,long nPos) throws IOException ]W|RtdF3.N
{ K Dz]wNf
oSavedFile = new RandomAccessFile(sName,"rw"); %%x0w^
this.nPos = nPos; r4S=I
oSavedFile.seek(nPos); k) 3s?
} ;r=?BbND?
f~v"zT
b\M b*o
public synchronized int write(byte[] b,int nStart,int nLen) 3 9yz~
{ VK$zq5D
int n = -1; tzmETRwG
try{ EFv4=OWB
oSavedFile.write(b,nStart,nLen); :'ihE\j
n = nLen; f:FpyCo=9
} :4]J2U\@
catch(IOException e) JQH7ZaN
{ tKX}Ok:V%
e.printStackTrace (); )?9\$^I
} U>1b9G"_
VX&WlG`wa
:OX$LCi
return n; E6JV}`hSk
} [nC4/V+-
$&Ac5Zo%}
+qZc} 7rJF
} k)Zn>
P_mi)@
2gH_$
/* AW62~*
**SiteInfoBean.java mMslWe
*/ ?}v}U^
package NetFox; lnjL7x
`L;OY 4
Bjtj{B
public class SiteInfoBean { CJ:uYXJJ:z
/xF 9:r
6VGo>b;
private String sSiteURL; //Site's URL $oc9 |Q 7
private String sFilePath; //Saved File's Path {Bc#?n
private String sFileName; //Saved File's Name =_uol8v
private int nSplitter; //Count of Splited Downloading File ?|)rv
gDMAc/V`l
6g8M7<og9R
public SiteInfoBean() K^8@'#S
{//nSplitter的缺省值为5 mUiOD$rO
//default value of nSplitter is 5 8Y7 @D$=w
this("","","",5); srhFEmgN7)
} !4_!J (q%
;i/"$K
/jvOXS\M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) we }#Ru*
{ Hl!1h%
sSiteURL= sURL; G}s;JJax
sFilePath = sPath; Q^vGj</u
sFileName = sName; SC]6F*
this.nSplitter = nSpiltter; 7 s7}?l9
]u~Os<
W.z$a.<(rF
} fHLFeSfH
aQxe)
A}gYcc85Z
public String getSSiteURL() $m{{,&}k
{ CJ0$;et
return sSiteURL; wXP_]-
} /#@LRN<oCq
o}d2N/T
PVZEB
public void setSSiteURL(String value) 9x4wk*z
{ +BU0 6lLD
sSiteURL = value; 3e#x)H/dr
} 8f|9W%jt
Z4=_k{*
N'I?fWN!;R
public String getSFilePath() PQ6T|>
{ r$94J'_
return sFilePath; "sdcP8])d
} <.;@ksCPW{
vM5k4%D
(H'_KPK
public void setSFilePath(String value) GOUY_&}tL
{ ?Ozk^#H[
sFilePath = value; i:MlD5 F
} lkI8{
[^h/(a`
oZ?IR#^
public String getSFileName() qxRT1B]{Wx
{ 22l|!B%o
return sFileName; I|GV :D
} 6wa<'!
8''9@xz
~3LhcU-
public void setSFileName(String value) s$K@X `
{ z?8zFP
sFileName = value; P9 W<gIO
} mvUVy1-c
cpP.7ZR
9|us<k
public int getNSplitter() %Y#[%~|(
{ r0rJ.}!
return nSplitter; &f (sfM_n
} AaJ,=eQ
@SX%? mk8G
[GcA.ABz
public void setNSplitter(int nCount) A}az m>
{ d,Im&j_Z
nSplitter = nCount; ]9bh+
} -U/I'RDLEz
} X; e`y:9
CUAg{]
KfJ c
/* l:>qR/|m
**Utility.java |;xfe"]
*/ ^EnNbFI
package NetFox; nPQZI6>
r*~n`
'[7C~r{%
public class Utility { l4R<`b\Jt
k1~nd=p
JKEXYE
public Utility() ?yK%]1O
{ p,_6jdz
T%N~oa
Z&?+&q r^
} "<g?x`iz
-f-O2G=
//线程睡眠 t-?KKU8
public static void sleep(int nSecond) uIVTs9\
{ *!wO:<-
try{ .3S\Rrv
Thread.sleep(nSecond); ,_wm,
} E@\d<c.
catch(Exception e) p@!@^1j=
{ X#f+m) S
e.printStackTrace (); .=et{\
} USHlb#*
} _Ex*%Qf.
Q]2sj:
//日志 yhJA;&}>
public static void log(String sMsg) *Bb|N--jI
{ YU ]G5\UU
System.err.println(sMsg); cq@_*:~Or
} L*SSv wSL
hPEp0("
W>t&N
public static void log(int sMsg) 1DI"LIL
{ N4Fy8qU;
System.err.println(sMsg); ci{9ODN
} FBwncG$]F*
} ;?O883@r8
xqi*N13
]IbPWBX
/* r=iMo7q
**TestMethod.java @?^LxqAWA
*/ d =B@EyN
package NetFox; J;Z>fAE7
yccuTQvz
Wzf1-0t
public class TestMethod { f3%^-Uy*b
+UpMMh q
#sm_.?P
public TestMethod() Zh fD`@>&
{ ///xx/weblogic60b2_win.exe ="'P=Xh!8
try{ J6^Ct
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); fW4cHB9|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [iO$ c]!H
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,;+91lR3
fileFetch.start(); P(YG@
} NP<F==,
catch(Exception e){e.printStackTrace ();} HIWmh4o/.
0F0Q=dZ
Aa\=7
} $<>EwW
bVAgul=__
%t5BB$y
public static void main(String[] args) bCaPJ!ZO
{ 4HJZ^bq9|
new TestMethod(); +DbWMm
} "o5gQTwb
} mC[U)` ey
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