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)); ul:jn]S*
} NQOdgp
for(int i=0;i<nEndPos.length-1;i++) ^ sz4rk
{ e06r5%|.%
nEndPos = nStartPos[i+1]; VJPt/Dy{
} Vdjca:`
nEndPos[nEndPos.length-1] = nFileLength; f6z[k_lLN
} O/FQ'o1F
} sqkPC_;A
K/08F|]a
Xf.SJ8G
//启动子线程 R[9[lQ'vR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5` Q#2
for(int i=0;i<nStartPos.length;i++) }96^OQPE
{ Q2+e`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,H|V\\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Iz ,C!c
nStartPos,nEndPos,i); qEywExdiu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J0{0B=d;
fileSplitterFetch.start(); Er%nSH^"
} e\)PGjSI
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tW 9vo-{+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /Jo*O=Lpo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f):|Ad|
nEndPos = " + nFileLength); O* 7"Q&
// fileSplitterFetch[nPos.length-1].start(); -()CgtSR
AJj6@hi2P
p!HpqW
//等待子线程结束 uv Z!3UH.
//int count = 0; =WHdy;
//是否结束while循环 V a<L[8
boolean breakWhile = false; p-;*K(#X
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%SIbpk%
while(!bStop) _TkiI.'
{ 8?ZK^+]y
write_nPos(); xC{W_a(
Utility.sleep(500); >8QLo8)3C
breakWhile = true; t.3b\RV[
k|&@xEbS
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for(int i=0;i<nStartPos.length;i++) tLLP2^_&
{ pWeKN`
if(!fileSplitterFetch.bDownOver) l].dOso$`
{ O,hT< s "
breakWhile = false; VBy=X\w]
break; V:yia^1
} \]GBd~i<
} j]YS(Y@AY
if(breakWhile) >+&524xc
break; eAPGy-
JH5ckgdZ
=r#of|`Q
//count++; \y{C>!WX4
//if(count>4) @/7tN3O
// siteStop(); eR=P
} Hh,q)(Wo
]^E<e!z={$
oS, %L
System.err.println("文件下载结束！"); =M>pL+#
} F!'y47QD
catch(Exception e){e.printStackTrace ();} tpU[KR[-
} *i&ks>4N
bF<FX_}!s!
8|HuxE
//获得文件长度 }H\wed]F/
public long getFileSize() M2{{B^*$6
{ ]~GwZB'M
int nFileLength = -1; )}tI8
try{ oBpHmMzA
URL url = new URL(siteInfoBean.getSSiteURL()); 4Y;z46yM%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iJT_*,P^
httpConnection.setRequestProperty("User-Agent","NetFox"); )Z,O*u*
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=:uK$>[
int responseCode=httpConnection.getResponseCode(); X=8y$Yy
if(responseCode>=400) }f/ 1
{ )|zLjF$
processErrorCode(responseCode); Etj@wy/E
return -2; //-2 represent access is error ~#C7G\R
} Ho2#'lSKM
&Y4S[-
1pg&?L.MA
String sHeader; **N{XxdN
f,9/Yg_
")}^\Om
for(int i=1;;i++) Uf4A9$R.G
{ >^=upf/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *2P%731n5
//Utility.log(in.readLine()); \oA>%+]5
sHeader=httpConnection.getHeaderFieldKey(i); &s-iie$"@x
if(sHeader!=null) !:]CKbG
{ Cjc>0)f&.
if(sHeader.equals("Content-Length")) +`}QIp0
{ ibAZ=RD
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Arc6d5Q
break; aA7}>
} 3"FvYv{
} }>]V_}h
else &{-r 5d23
break; m<}>'DT
} r~nD%H:}P
} `tw[{Wb
catch(IOException e){e.printStackTrace ();} B:J([@\'
catch(Exception e){e.printStackTrace ();} <Nwqt[.
JFewOt3
(E[c-1s
Utility.log(nFileLength); ]Dec/Nnj
y(^t&tgjS
<n? cRk'.
return nFileLength; '{*{
} \MI2^JN
j*Uz.q?
'guXdX]Gu
//保存下载信息（文件指针位置） 3CcCcZ9I
private void write_nPos() X$BN&DD
{ fqpbsM;M]
try{ Pu>jECcz
output = new DataOutputStream(new FileOutputStream(tmpFile)); >>bsr#aJ
output.writeInt(nStartPos.length); +-2o b90_m
for(int i=0;i<nStartPos.length;i++) :8h\x
{ B8.a#@R
// output.writeLong(nPos); &YpViC4K.
output.writeLong(fileSplitterFetch.nStartPos); CiF(
output.writeLong(fileSplitterFetch.nEndPos); ( f]@lNmx
} EdcbWf7
output.close(); QiKci%=SX
} x$hhH=
catch(IOException e){e.printStackTrace ();} Bm"-X:='
catch(Exception e){e.printStackTrace ();} r ]s7a?O
} 3EkCM_]
X\4d|VJ?m
fJ<I|ZZ
//读取保存的下载信息（文件指针位置） iq1HA.X(
private void read_nPos() .bYZkO:oy
{ &X3G;x2;
try{ 03pD<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <fSWX>pR
int nCount = input.readInt(); -d>2&)5
nStartPos = new long[nCount]; `)y<X#[8
nEndPos = new long[nCount]; 00SYNG!
for(int i=0;i<nStartPos.length;i++) >^:*x_a9
{ WoV"&9y
nStartPos = input.readLong(); |#(KP
nEndPos = input.readLong(); A:b(@'h
} 1aAY7Dm_&
input.close(); I%(YR"
} NTWy1
catch(IOException e){e.printStackTrace ();} aC90IJ8^
catch(Exception e){e.printStackTrace ();} _+7+90u
} 0Wkk$0h9
S@Iza9\|@
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private void processErrorCode(int nErrorCode) eR3v=Q
{ Kd r7 V
System.err.println("Error Code : " + nErrorCode); ;O`ZVB
} atiyQuT6Wh
ES}V\k*}
\qf0=CPw8
//停止文件下载 kz_gR;"(Z
public void siteStop() O:E0htdWr
{ ZWmS6?L.
bStop = true; jlxY|;gZ-0
for(int i=0;i<nStartPos.length;i++) YY zUg
fileSplitterFetch.splitterStop(); b1TIVK3m
]J1oY]2~
yopC <k
} =cR"_Z[8X
} 9\'JtZO
//负责部分文件的抓取 `' .;U=mF
**FileSplitterFetch.java HVdy!J
*/ 4bs<j
package NetFox; \E(^<Af
~U r
gU&y5s~
import java.io.*; 8$F"!dc _
import java.net.*; CM%Rz-c
5^ck$af
38GkV.e}$
public class FileSplitterFetch extends Thread { m]+~F_/
K'Y/0:"*
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String sURL; //File URL u{-@,-{
long nStartPos; //File Snippet Start Position q4#$ca[_ak
long nEndPos; //File Snippet End Position ))%f"=:wt
int nThreadID; //Thread's ID U)[LKO1
boolean bDownOver = false; //Downing is over C:AD ZJL
boolean bStop = false; //Stop identical A`~R\j
FileAccessI fileAccessI = null; //File Access interface i/.#`
=,b6yV+$D
4^Ss\$*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1=Kt.tuf
{ ^IgQIN
this.sURL = sURL; 8NkyT_\
this.nStartPos = nStart; dl.gCiI
this.nEndPos = nEnd; Cag^$nj
nThreadID = id; N~uc%wOA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 S zNZY&8 f
} Bs`mzA54
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{'Y()p3kl
public void run() sWmqx$
{ \G#_z|'dN
while(nStartPos < nEndPos && !bStop) eQz.N<f"
{ c/7}5#Rs
h`dHk]O
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try{ [_eT{v2B4
URL url = new URL(sURL); )&DsRA7v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {,!!jeOO
httpConnection.setRequestProperty("User-Agent","NetFox"); -{}(U
String sProperty = "bytes="+nStartPos+"-"; #<~oR5ddlb
httpConnection.setRequestProperty("RANGE",sProperty); *>/w,E]
Utility.log(sProperty); Lv?jg?$
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<0VC`+p<)
InputStream input = httpConnection.getInputStream(); ihJ!]#Fbm
//logResponseHead(httpConnection); ch2m Ei(
+DG-MM%\
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byte[] b = new byte[1024]; mGDy3R90
int nRead; E-%$1=;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R$!]z(
{ [+d~He
nStartPos += fileAccessI.write(b,0,nRead); <BIQc,)2}
//if(nThreadID == 1) ;m7~!m)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {qGXv@ I6
} rd>>=~vx=/
\2!.
k`#E#1niN
Utility.log("Thread " + nThreadID + " is over!"); |$;4/cKfy
bDownOver = true; _&(L{cFx6
//nPos = fileAccessI.write (b,0,nRead); T6b~uE
} F Uz1P
catch(Exception e){e.printStackTrace ();} nuDu
} <ne?;P1L
} |"PS e~ u
GSs?!BIC
q:nUn?zB
//打印回应的头信息 3ZC@q #R A
public void logResponseHead(HttpURLConnection con) ,Ne9x\F
{ (t){o>l
for(int i=1;;i++) !rs }83w!
{ ]cv/dY#
String header=con.getHeaderFieldKey(i); nrA 4N1
if(header!=null) T+x /J]A
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lI%RdA[
Utility.log(header+" : "+con.getHeaderField(header)); Wy\^}
else BL~#-Mm<|l
break; C=CZtjUt
} qRgFVX+vc
} w:9`R<L
5VpqDL~d
=`*@OJHH
public void splitterStop() {Mj- $G"
{ KwV!smi2
bStop = true; }9^'etD
} Buso `G
=E$bZe8
A9g/At_
} p0y|pD
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~3-"1E>Rgy
/* RX%)@e/@
**FileAccess.java nGwon8&]]
*//文件访问(定位，写) U.V/JbXX
package NetFox; dGj0;3FI%
import java.io.*; tK@7t0
s?s,wdp
HL]J=Gh
public class FileAccessI implements Serializable{ pacD7'1{
;&gk)w6*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4%zy$,|e
RandomAccessFile oSavedFile; Pwj|]0Y@
long nPos; S(U9Dlyarg
#>HY+ ;
~ o2Z5,H
public FileAccessI() throws IOException jz HWs
{ e`U 6JzC
this("",0); 5~Ek_B
} kN3 <l7
0'THL%lK
<KK.f9^o(
public FileAccessI(String sName,long nPos) throws IOException x_I*6?
{ #_x5-?3
oSavedFile = new RandomAccessFile(sName,"rw"); Xn?.Od(
this.nPos = nPos; `1n^~
oSavedFile.seek(nPos); Qd\='*:!
} cl1ygpf(
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9BpxbU+L;
public synchronized int write(byte[] b,int nStart,int nLen) /F9Dg<#a
{ j!NXNuy:
int n = -1; g\q4-
try{ qBcbMa9m
oSavedFile.write(b,nStart,nLen); oemN$g&7
n = nLen; SUIJ{!F/
} `R xCs`
catch(IOException e) &;pM<h
{ ?%8%1d
e.printStackTrace (); *U6+b
} ;du},>T$n
/\<x8BJ
Z*f%R\u
return n; 'K02T:\iZ
} l`l6Y>c*]
^|zag
_68vSYr
} XkkzY5rxOc
!;mn]wR>a
iLJ@oM;2
/* yGNpx3H
**SiteInfoBean.java F!g1.49""
*/ rNJU & .]
package NetFox; o~e_M-
]T|$nwQ
fMUh\u3
public class SiteInfoBean { !ht2*8$lQ
Wu<;QY($5
@k)J i!7
private String sSiteURL; //Site's URL P7zUf
private String sFilePath; //Saved File's Path 6M`gy|"(~
private String sFileName; //Saved File's Name )eT>[['fm
private int nSplitter; //Count of Splited Downloading File hu} vYA7ZH
vf@j d}?
1$.svR
public SiteInfoBean() ;+(_stxqV9
{//nSplitter的缺省值为5 /n(0w`
//default value of nSplitter is 5 `p9N| V
this("","","",5); V sxI
} [;7zg@Sa
4i{Xs5zk
<9 ^7r J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G1w$lc
{ AaxQBTB
sSiteURL= sURL; QW,:'\G
sFilePath = sPath; ~XP|dn}
sFileName = sName; 7S 8X)
this.nSplitter = nSpiltter; 0>BI[x@
pZeOdh
S>h\D4.
} 8x)i{>#i
$:oC\K6
MZX)znO
public String getSSiteURL() 0;T7fKj
{ I}o} #OJ
return sSiteURL; )D#}/3s
} eGg6wd
fNu/>pN
qD\9h`a
public void setSSiteURL(String value) 1$Q[%9
{ QwpX3 k6
sSiteURL = value; 'h0>]A 2|X
} mRC3w(W
:<B_V<
dmXfz D
public String getSFilePath() @v@F%JCZ
{ |>xuH#Q
return sFilePath; bo90;7EK8
} 6'N_bNW
QtG6v<A
ps:`rVQ7
public void setSFilePath(String value) `?R{sNr.
{ _*?qOmf=
sFilePath = value; O9d"Z$~n=j
} <`=Kt[_BQ
VVAcbAGJ
UCmy$aW
public String getSFileName() -Z:x!M[Xr
{ QN$s%&O
return sFileName; &PL=nI\)
} Rh)XYCM
y;fF|t<y
LI3L~6A>
public void setSFileName(String value) )P b$
{ h9imS\gfr
sFileName = value; W!\%v"
} kiN,N]-V
G%l')e)9Gq
j7Y7&x"
public int getNSplitter() )4qspy3
{ S .x>w/
return nSplitter; %JiF269
} ?)(/SZC0
]o"E4Vht
X[tB^`
public void setNSplitter(int nCount) |hi,]D^Kc
{ fVY I
nSplitter = nCount; G8__6v~
} SE'|||B
} DMsqTB`
!e<2o2~.
z8"1*V
/* _<mY|
**Utility.java ?t6wozib2
*/ {*hvzS{1d
package NetFox; e~(e&4pb
!idVF!xG
[o(!/38"@=
public class Utility { RV{%@1Pu
H.>EO&#|p
H<fi,"X^
public Utility() # }}6JM
{ Dzu//_u
BH~zeJ*Pr
r0[<[jEh
} 8N"WKBj|_d
\MmOI<Hd-
//线程睡眠 eHs38X
public static void sleep(int nSecond) x"C7NW[$
{ R+K|K2"
try{ S&IW]ffK
Thread.sleep(nSecond); _oG%bNM
} nIlTzrf6
catch(Exception e) l1<=3+d
{ <a=OiY
e.printStackTrace (); Hik=(pTu>
} oLX[!0M^
} t>N2K-8Qh
T+B-R\@t
//日志 qyVARy
public static void log(String sMsg) %B#T"=Cx
{ 1QD49)
System.err.println(sMsg); 6XZjZ*)W
} H{N},B
XY? Cl
fB7Jx6
public static void log(int sMsg) MS#*3Md&y
{ VO {z)_
System.err.println(sMsg); oGI'a:iff
} z^tzP~nI
} T*#M'H7LSQ
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D4hT Hh
/* U*yOe*>
**TestMethod.java QP50.P5g
*/ dwUDhQt3Q
package NetFox; B-KMlHe
n^|xp;] :
JCBX?rM/
public class TestMethod { "HqmS
P* &0HbJ
d*6/1vyjT
public TestMethod() Z]DZ:dF
{ ///xx/weblogic60b2_win.exe S~fP$L5
try{ DHeZi3&i
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C%E~9_w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J| wk})?
SiteFileFetch fileFetch = new SiteFileFetch(bean); FF^h(Ea
fileFetch.start(); 1Vz^?t:
} "PN4{"`V
catch(Exception e){e.printStackTrace ();} ,66(*\xT
VR1]CN"G
sk8DW
} $")Gd@aR
< -W8
ge?0>UU;~
public static void main(String[] args) }|;j2'(R
{ I9xu3izAmR
new TestMethod(); (b[=~Nh'
} owA8hGF
} C<9GdN
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