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)); *cEob b
} DZ_lW
for(int i=0;i<nEndPos.length-1;i++) nB!&Zq
{ $#]]K
nEndPos = nStartPos[i+1]; rta:f800z
} -N"&/)
nEndPos[nEndPos.length-1] = nFileLength; 0@EwM
} qM.bF&&Go
} 4T=u`3pD7l
kV38`s>+
N2w"R{)j\
//启动子线程 3"P }n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5sb\r,kW
for(int i=0;i<nStartPos.length;i++) eQ&ZX3*}
{ Ry|!pV
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8KRba4[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6qp%$>$Vt;
nStartPos,nEndPos,i); -e8}Pm "
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Hbpqyl%O>
fileSplitterFetch.start(); /"B?1?qc,=
} RoyPrO [3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &SrO)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CjiVnWSz<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d$ ^ ,bL2p
nEndPos = " + nFileLength); ?`4+cx}n
// fileSplitterFetch[nPos.length-1].start(); zSFDUZ]A3
phgm0D7
aAB`G3
//等待子线程结束 A7n\h-b
//int count = 0; CXC`sPY
//是否结束while循环 yfm^?G|sW
boolean breakWhile = false; 8)4P Ll
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&0`) Q
while(!bStop) h}xeChw]
{ %%4t~XC#
write_nPos(); 3:C oZ
Utility.sleep(500); *Q,0W:~-
breakWhile = true; d.P\fPSD
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zA1lca0HK
for(int i=0;i<nStartPos.length;i++) -*XCxU'
{ nI*v820,
if(!fileSplitterFetch.bDownOver) ;dzL}@we
{ /jRRf"B
breakWhile = false; }|XtypbL
break; Q^#;WASi
} u5Ftu?t
} >2Kh0rIH
if(breakWhile) ^Y iJV7
break; QI3Nc8t_2
9J?wO9rI
IzpZwx^3''
//count++; /<]{KI
//if(count>4) ?G-e](]^<
// siteStop(); _C`K*u 6Z<
} sUU{fNC6|
x(eb5YS
1SR+m>pL
System.err.println("文件下载结束！"); r}jGUe}d
} k0Uyf~p~
catch(Exception e){e.printStackTrace ();} !H}vu]R
} iV eC=^1
.3MIcj=p
/\WQxe
//获得文件长度 <0PT"ij
public long getFileSize() ,.qMEMm
{ r9ww.PpNk#
int nFileLength = -1; f?'JAC*
try{ wV^V]c?U
URL url = new URL(siteInfoBean.getSSiteURL()); m2v'WY5u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |\g5+fv9
httpConnection.setRequestProperty("User-Agent","NetFox"); a!u rew#
j<)9dEM'
INyk3`FT
int responseCode=httpConnection.getResponseCode(); )}_a 0bt
if(responseCode>=400) XQ~Ke-QW)
{ \} ^E`b
processErrorCode(responseCode); [mPjP%{=@
return -2; //-2 represent access is error @!8ZPiW<
} d:i;z9b@to
MKWyP+6`
#Z<a
String sHeader; 6KOlY>m]
1"e)5xI
.fdL&z
for(int i=1;;i++) _X'"w|0
{ PfZ+PqS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [Ts"OPb%~
//Utility.log(in.readLine()); hjQ~uqbg
sHeader=httpConnection.getHeaderFieldKey(i); I*`*Q$
if(sHeader!=null) 8{Fsm;UsY
{ dH^<t,v
if(sHeader.equals("Content-Length")) ,-OCc!7K
{ ;jipe3LU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xQ'2BAEa
break; 4sP2g&
} w-0mzk"
} q=9`06
else {pHM},WJ
break; dS5a
} l}lIi8
} w&%~3Cz.
catch(IOException e){e.printStackTrace ();} ubmrlH\d
catch(Exception e){e.printStackTrace ();} aN,M64F
$e /^u[~:
bk\yCt06y;
Utility.log(nFileLength); VV9_`myN7
-k7X:!>QHC
bcZf>:gVf
return nFileLength; jr`Ess
} -c}, :G"
+(+Itmx2&
q]\g,a
//保存下载信息（文件指针位置） d`(@_czdF
private void write_nPos() =lu/9 i6
{ @_LN3zP
try{ zdp/|"D!
output = new DataOutputStream(new FileOutputStream(tmpFile)); %:2+ o'
output.writeInt(nStartPos.length); _{ZqO;[u
for(int i=0;i<nStartPos.length;i++) %=BMZRn
{ EKzAd
// output.writeLong(nPos); r]0 lo-
output.writeLong(fileSplitterFetch.nStartPos); 5A4&+rdU
output.writeLong(fileSplitterFetch.nEndPos); 0p@k({]<
} s|NjT
output.close(); Uk,gJR
} <3j"&i]Tm*
catch(IOException e){e.printStackTrace ();} k{<,\J
catch(Exception e){e.printStackTrace ();} ;-Jb1"5
} ScSZGs 5&
ru7RcYRq
Dxk+P!!K
//读取保存的下载信息（文件指针位置） B)QHM+[=F
private void read_nPos() 9Fr3pRIJ
{ po}F6m8bX
try{ 6AWKLFMV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {N#KkYH{"
int nCount = input.readInt(); DSj(]U~r
nStartPos = new long[nCount]; UYz0PSV=.
nEndPos = new long[nCount]; 8dlw-Q'S
for(int i=0;i<nStartPos.length;i++) @e'5E^
{ RAp=s
nStartPos = input.readLong(); 0{j&6I2
nEndPos = input.readLong(); f +hjC
} JXj8Br?Z@
input.close(); <u=4*:QE
} |> _!eS\=<
catch(IOException e){e.printStackTrace ();} >pr=|$zk=
catch(Exception e){e.printStackTrace ();} dqX;#H}h
} G\a8B#hg
_H^^y$+1
SKW%X8
private void processErrorCode(int nErrorCode) L-9~uM3@\
{ ys#i@
System.err.println("Error Code : " + nErrorCode); E.iSWAJ(w
} &V)6!,rb
~QZ"Z tu
10#f`OPC
//停止文件下载 (4%YHS8
public void siteStop() g(|6~}|o+
{ ?r2#.W
bStop = true; $8crN$ye
for(int i=0;i<nStartPos.length;i++) 0=="^t_
fileSplitterFetch.splitterStop(); c1xrn4f@a
*;XWLd#
Y+3!f#exm
} w2xG_q
} u@3y&b
//负责部分文件的抓取 A?*o0I
**FileSplitterFetch.java ^xZ e2@
*/ $v b,P(
package NetFox; c c
=-o'gL
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import java.io.*; &k8vWXMGk%
import java.net.*; w;e(Gb%9
uZi.HG{<)
&,.Y9; b
public class FileSplitterFetch extends Thread { Ei2%DMN7)
U/NBFc:[y:
JO'>oFv_W
String sURL; //File URL c)7j QA
long nStartPos; //File Snippet Start Position :h1pBEiH
long nEndPos; //File Snippet End Position zW8*EE+,
int nThreadID; //Thread's ID Hp|}~xjn
boolean bDownOver = false; //Downing is over v0Ir#B,[H
boolean bStop = false; //Stop identical ]p!Gt,rYq
FileAccessI fileAccessI = null; //File Access interface -TV?E%r
cc44R|Kr$$
O6].*25
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {ccIxL /~
{ 7_# 1Ec|;
this.sURL = sURL; 4c+$%pq5
this.nStartPos = nStart; ^W7X(LQ*+
this.nEndPos = nEnd; '>(.%@
nThreadID = id; j8K,jZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Xo{`]
} #*>E*#?t
{w <+_++
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public void run() RL[E X5U
{ .O0O-VD+a
while(nStartPos < nEndPos && !bStop) 9GdB#k6W`
{ 3u33a"nL8
8by@iQ
Y$-3v.
try{ 9,]5v+
URL url = new URL(sURL); ?tg y|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `O6:t\d@
httpConnection.setRequestProperty("User-Agent","NetFox"); k6Cn"2q <
String sProperty = "bytes="+nStartPos+"-"; H7[6yh
httpConnection.setRequestProperty("RANGE",sProperty); tMj1~ R
Utility.log(sProperty); Ay{t254/
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aJqeD'\>
InputStream input = httpConnection.getInputStream(); !rhk $L
//logResponseHead(httpConnection); eb|i3.
$c&0F,
a8AYcEb
byte[] b = new byte[1024]; yA[({2%
int nRead; B ZMu[M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `)4a[thp
{ [4J6iF
nStartPos += fileAccessI.write(b,0,nRead); 4ujvD^
//if(nThreadID == 1) t_ur&.^SB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MP>n)!R[`
} e&9F\e
@uH#qg7
_DP|-bp D
Utility.log("Thread " + nThreadID + " is over!"); ~svO*o Wa
bDownOver = true; smQVWs>
//nPos = fileAccessI.write (b,0,nRead); _;RVe"tR#
} {I{:GcS
catch(Exception e){e.printStackTrace ();} $ex!!rqN|
} {0YAzZ7
} N{d@^Yj
b @;.F!x
pe&UQ C^
//打印回应的头信息 (ozb%a#B
public void logResponseHead(HttpURLConnection con) O3NWXe<
{ [t0rfl{.
for(int i=1;;i++) /b,TpuM^
{ TQ9D68 ,
String header=con.getHeaderFieldKey(i); iwY'4Z e
if(header!=null) YW; Hk1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N6Z{BLZ
Utility.log(header+" : "+con.getHeaderField(header)); ]|:uU
else vs&8wbS)
break; Dmdy=&G
} 8n?kZY$,
} 9j|gdfb%ml
kVDe6},D7
%|XE#hw
public void splitterStop() Rn+4DcR
{ 1QJBb \
bStop = true; Ps R>V)L
} mE#nU(+Ta
s* jfMY
]qw0V
} bZipm(e
")lw9t`
.+K S`
/* B>TSdn={>
**FileAccess.java D!TZI
*//文件访问(定位，写) l*7?Y7FK
package NetFox; +'03>!V
import java.io.*; K6pR8z*?
D>wZ0p b-
_`a&9i &
public class FileAccessI implements Serializable{ ;8B.;%qkL
CHaE;olo
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #2%([w
RandomAccessFile oSavedFile; {8NwFN.
long nPos; So4nJ><p
]7qiUdxt:
fUcLfnr
public FileAccessI() throws IOException d34Y'r
{ 8V5a%2eV
this("",0); ;6DnId2Zh
} -fIc4u[
w}<^l
NW.XA! =E)
public FileAccessI(String sName,long nPos) throws IOException CB*/ =Y
{ [N|xzMe
oSavedFile = new RandomAccessFile(sName,"rw"); {0's~U+@
this.nPos = nPos; g*-2* \
oSavedFile.seek(nPos); N\R=cwk
} Rrqg[F+
u.6P-yh
u3dsQU
public synchronized int write(byte[] b,int nStart,int nLen) .2X2b<%)
{ vD=%`G[m
int n = -1; H+cNX\,
try{ `Q9+k<
oSavedFile.write(b,nStart,nLen); WD?Jk9_F
n = nLen; T{-2fp8r[
} 3eg5oAZ)G8
catch(IOException e) ^Omfe
{ |f NMs
e.printStackTrace (); |Cf mcz(56
} =,Ttw>
-i_En^Fi
~b8a^6:R"
return n; ]C *10S`
} AQ@v>wr}
NJ$e6$g)
%D^bahf
} &`@M8-m#F
/4C`k=>
eF1.VLI
/* yDtOpM8<{
**SiteInfoBean.java $pFk"]=
*/ f9'] jJ+
package NetFox; "T*I|
?~)Ak`=
0>Fqx{!heq
public class SiteInfoBean { Vj!WaN_
0$2={s4ze
K/Jk[29"\
private String sSiteURL; //Site's URL KO-a; [/
private String sFilePath; //Saved File's Path MFTC6L+T
private String sFileName; //Saved File's Name qeMv Vf
private int nSplitter; //Count of Splited Downloading File fq Y1ggL
p\+6"28{_~
$Q4=37H+
public SiteInfoBean() nW&$~d
{//nSplitter的缺省值为5 rv?!y8\
//default value of nSplitter is 5 2nx9#B*/T
this("","","",5); vPsq<l}
} X,Zd=
#{w5)|S#JD
g8Aj `O
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) D-iUN
{ lJj&kVHb
sSiteURL= sURL; MOLO3?H(
sFilePath = sPath; 6S_y%8Fv&[
sFileName = sName; 0UD"^zgY
this.nSplitter = nSpiltter; 1"$R 3@s;
tDU}rI8?
;z0"Ox=7
} oeGS
Bbs5f@E
f+^c@0que
public String getSSiteURL() xOM_R2Md
{ 08io<c,L
return sSiteURL; 'Q`C[*c
} ^;64!BaK
m >hovikY*
R.UumBM
public void setSSiteURL(String value) k.{G&]r{
{ M8Juykw
sSiteURL = value; gA:[3J,[;
} CK Mv7
Z^+a*^w~{
D1! {S7
public String getSFilePath() 1t%<5O;R
{ P#F_>GB
return sFilePath; q]+)c2M
} i;avwP<0
S[.5n]
TnxU/)
public void setSFilePath(String value) 9C>ynH
{ qSR?,G
sFilePath = value; V7n >,k5
} <THUsY`3P&
xiJz`KD&
V^ Y*xZ
public String getSFileName() 'ucGt
{ h=Oh9zsz8
return sFileName; dv[\.T`LY
} J5-rp|
3z$HKG
RSFJu\0}N
public void setSFileName(String value) jDJ.
{ Hz5;Ruw'
sFileName = value; sM0c#YK?
} Kv1vx*>
<]c#)xg
o6/Rx#A
public int getNSplitter() .&L^J&V
{ ^^'[%ok
return nSplitter; 9Yd-m
} UXQb={
}`4K)(>4nG
SCI1bMf
public void setNSplitter(int nCount) &EGY+p|2Y
{ Kj=;>u
nSplitter = nCount; 8`DO[Z
} pB[%:w/@l:
} .oEFX8
SUo^c1)G
+=Yk-nJ
/* GtG&yeB
**Utility.java :(+]b
*/ b%<164i
package NetFox; yX3PUO9
phe"JNML
IF& PGo
public class Utility { G1p43
F"Uh/EO<
U~Xf=f_Q$
public Utility() 2[XltjO
{ M,ppCHy/$
?C FS}v
TJE% U0Ln
} N*HH,m&
u1wg C#
//线程睡眠 kz$(V(k<
public static void sleep(int nSecond) >QA/Mi~R
{ 'G52<sF
try{ #i@ACAgn;6
Thread.sleep(nSecond); otoBb^Mz
} M9h<}mh\
catch(Exception e) HUK"OH
{ (K<Z=a
e.printStackTrace (); Tln9q0"W
} w<v1N
} _F3KFQ4,S-
`B:B7Cpvn
//日志 (/('nY
public static void log(String sMsg) 2B5A!?~>
{ Jk%'mEGE
System.err.println(sMsg); (21']x
} zUNH8=U
10/x'#(
Q%+}
public static void log(int sMsg) #aj|vox}
{ H\ {E%7^h-
System.err.println(sMsg); fm[_@L% x
} VjC*(6<Gj
} te4F"SEf
/A0 [_
h=!M6yap<
/* : x>I- 3G
**TestMethod.java D!c1;IHZ
*/ wwo(n$!\
package NetFox; j!6elzg
n9N#&Q"7m
$+A%ODv
public class TestMethod { 'y'T'2N3
=U=e?AOG2
Czq1 kz
public TestMethod() xX[?L9RGz
{ ///xx/weblogic60b2_win.exe <Z2(qZ^Z
try{ 1 ,#{X3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jB5>y&+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); lb-S0plw
SiteFileFetch fileFetch = new SiteFileFetch(bean); y{@P1{
fileFetch.start(); )!'Fa_$ e
} R5m`;hF
catch(Exception e){e.printStackTrace ();} hN Z4v/
vsu@PuqH
x%_qJ]o
} oNiToFbQu
:= ]sq}IN
JmnBq<&,0
public static void main(String[] args) R)sp
{ 3Ne9%"
new TestMethod(); i7i|370
} #;wkr))
} Uzan7A
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