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)); H,:Cg:E/^
} b;9v.MZ4>g
for(int i=0;i<nEndPos.length-1;i++) 7{v0K"E{
{ 08yTTt76t
nEndPos = nStartPos[i+1]; j)'V_@
} IC92lPM }
nEndPos[nEndPos.length-1] = nFileLength; _Dwn@{[(8
} _+z@Qn?#6h
} $J=9$.4"
= fuF]yL%
7s<v06Wo
//启动子线程 f!xIMIl)+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1PjSa4
for(int i=0;i<nStartPos.length;i++) zu*0uL
{ AG/nX?u7)t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w+2:eFi=/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7.8ukAud
nStartPos,nEndPos,i); RTHdL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [^1;8Tbk
fileSplitterFetch.start(); kxThtjgv
} wf6ZzG:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @>(l}5U5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1S 0GjR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", x%vt$dy*8
nEndPos = " + nFileLength); , $78\B^
// fileSplitterFetch[nPos.length-1].start(); ^^3 >R`
i.0}qS?
i*9eU*i|H
//等待子线程结束 o Ep\po1
//int count = 0; =QRLKo#_
//是否结束while循环 H]}Iw5Z
boolean breakWhile = false; 8 6?D
eZI&d;i
xyBe*,u
while(!bStop) qNC.|R
{ csH1X/3ha\
write_nPos(); qGl+KI
Utility.sleep(500); vb5tyY0c
breakWhile = true; `r+e!o
v|t^th,
rZ w&[ G
for(int i=0;i<nStartPos.length;i++) Ij@YOt
{ r,[vXxMy(;
if(!fileSplitterFetch.bDownOver) '`/1?,=
{ dH&N<
breakWhile = false; ?!Rlp/
break; X<,sc;"b`k
} OHp 121
} ra_`NsKF}
if(breakWhile) fVb&=%e
break; g9GE0DbT`
~Jmn?9 3
UZmzk
//count++; py P5^Qv
//if(count>4) !_l W#feR
// siteStop(); ]c[80F-
} 'ZTE"KT
hb_YdnG
G80d!*7
System.err.println("文件下载结束！"); Ax=Rb B"
} !Lk|eGd*
catch(Exception e){e.printStackTrace ();} DE."XSni
} M!!W>A@T[g
eu^z&R!um
l'B`f)
//获得文件长度 QmT]~4PqS
public long getFileSize() 5<,}^4wWZ
{ :E@"4O?<Y)
int nFileLength = -1; -]W AB9
try{ c<pr1g
URL url = new URL(siteInfoBean.getSSiteURL()); [M Z'i/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IUbYw~f3
httpConnection.setRequestProperty("User-Agent","NetFox"); 2[qO;js
X/2Xr(z"k
{xr4CDP
int responseCode=httpConnection.getResponseCode(); LPO3B W
if(responseCode>=400) `)1_^# k
{ ZfL\3Mn
processErrorCode(responseCode); <CzH'!FJN
return -2; //-2 represent access is error .OX.z~":y
} B~caHG1b
F2!_Z=
nFX8:fZ$>
String sHeader; <M7@JgC &
Ia0.I " ,
psgXJe$
for(int i=1;;i++) [fxAj]
{ ;W'y^jp]"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v&xk?F?WU,
//Utility.log(in.readLine()); d]0fgwwGC
sHeader=httpConnection.getHeaderFieldKey(i); wu/]M~XwI
if(sHeader!=null) "'^#I_*Mf
{ Z[ZqQ` 7N
if(sHeader.equals("Content-Length")) D(@#Gd\Z@
{ Nt$/JBB[$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u6awcn
break; azS"*#r6}
} 7t0\}e
} 2oGl"3/p
else f,)[f M4
break; j42U|CuK
} LXJ"ct
} ?h<I:[oZ
catch(IOException e){e.printStackTrace ();} {y`afuiB
catch(Exception e){e.printStackTrace ();} Jc-0.^]E}
iVFHr<zk
UpN:F
Utility.log(nFileLength); n/=&?#m}d
[JO'ta
O<)"kj 7
return nFileLength; 4u"V52
} [`6|~E"F
.%M=dL>
v,KH2 (N
//保存下载信息（文件指针位置） '<^%>R2
private void write_nPos() 13'tsM&
{ /H:'(W_b;
try{ ;B:'8$j$
output = new DataOutputStream(new FileOutputStream(tmpFile)); J&@[=zBYw
output.writeInt(nStartPos.length); 4["$}O5
for(int i=0;i<nStartPos.length;i++) 15)=>=1mR.
{ K9mL1[B
// output.writeLong(nPos); 2(\~z@g
output.writeLong(fileSplitterFetch.nStartPos); s4@AK48
output.writeLong(fileSplitterFetch.nEndPos); #?@k=e\
} >wNE!Oa*B
output.close(); 8;5 UO,`T
} 3R !Mfz*
catch(IOException e){e.printStackTrace ();} Y@c!\0e$
catch(Exception e){e.printStackTrace ();} >dUnk)7
} WID4{>G2
S=U*is
%i]q} M
//读取保存的下载信息（文件指针位置） HH&`f3
private void read_nPos() ((SN We
{ w[^s)1
try{ 2ZNTj u7h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); nBgksB*A
int nCount = input.readInt(); Dr^#e
nStartPos = new long[nCount]; |O%`-2p]p
nEndPos = new long[nCount]; 7i`@`0
for(int i=0;i<nStartPos.length;i++) ]uI#4t~
{ q=M!YWz
nStartPos = input.readLong(); Hq?-e?Nc
nEndPos = input.readLong(); ]S[M]-I
} <Qe30_<K
input.close(); 7{ (t_N>
} *r6+Vz
catch(IOException e){e.printStackTrace ();} 8`EzvEm
catch(Exception e){e.printStackTrace ();} f]tc$`vb
} T$U,rOB"
:EJ+#
zqh.U@
private void processErrorCode(int nErrorCode) ;?"]S/16,
{ Smzy EMT
System.err.println("Error Code : " + nErrorCode); Wsyq
} lEL&tZ}
ykrb/j|rK
)@Fuw*
//停止文件下载 GS_'&Yj
public void siteStop() H4ml0SS^
{ +Em+W#i%?
bStop = true; |QHDg(
for(int i=0;i<nStartPos.length;i++) 2 1.;lj
fileSplitterFetch.splitterStop(); `rzgC \
MDGD*Qn~
jc)[5i0
} yANk(
} )R.y>Ucb0
//负责部分文件的抓取 vY&[=2=
**FileSplitterFetch.java n@<+D`[.V
*/ ]|ew!N$ar=
package NetFox; 8Ux3,X=
>0z(+}]3z
48l!P(>?y
import java.io.*; A0Pg|M
import java.net.*; Ea#wtow|-
MA0}BJoW
#!(OTeL
public class FileSplitterFetch extends Thread { 8R<2I1xn2
'o;>6u<u
:Lu=t3#
String sURL; //File URL 9aky+
long nStartPos; //File Snippet Start Position &~Qi+b0!
long nEndPos; //File Snippet End Position #\U;,r
int nThreadID; //Thread's ID ANh7`AUuO
boolean bDownOver = false; //Downing is over N=R|s$,Oy9
boolean bStop = false; //Stop identical k`ulDQu
FileAccessI fileAccessI = null; //File Access interface 4d~Sn81xW
C\#E1\d
>Z@^R7_W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C{AVV<
{ Sxo9y0K8-
this.sURL = sURL; l'TM^B)`c
this.nStartPos = nStart; |t](4
this.nEndPos = nEnd; Plpt7Pa_
nThreadID = id; OtK=UtVI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Qv=F'
} g*]Gc%
$KDH"J
MD`1KC_m
public void run() Bs7/<$9K/
{ 6bj.z
while(nStartPos < nEndPos && !bStop) IjJO;
{ !##OQ
7S+_eL^
t0t" =(d
try{ rq=D[vX\N(
URL url = new URL(sURL); |oCE7'BaP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6XU1w
httpConnection.setRequestProperty("User-Agent","NetFox"); lxsBXXZg
String sProperty = "bytes="+nStartPos+"-"; |-kU]NJFR
httpConnection.setRequestProperty("RANGE",sProperty); VsLlPw{
Utility.log(sProperty); x%<oeM3U
Y [8~M8QX
:f1Q0klwP
InputStream input = httpConnection.getInputStream(); wCT. (d_
//logResponseHead(httpConnection); yc ize2>q
Hqsj5j2i
;Ohabbj*
byte[] b = new byte[1024]; -1^dOG6*
int nRead; 9k5$rK`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %p?+r
{ ~ti{na4W<
nStartPos += fileAccessI.write(b,0,nRead); 0A$x'pU)
//if(nThreadID == 1) 3eOwy~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~cHpA;x9<^
} /"$A?}V
Ns3k(j16
5!GL"
Utility.log("Thread " + nThreadID + " is over!"); 7-p9IFcA
bDownOver = true; j A/xe
//nPos = fileAccessI.write (b,0,nRead); fC1PPgQ\
} i6)7)^nG
catch(Exception e){e.printStackTrace ();} iv3=J
} ;S,k U{F
} LI`L!6^l
WX2:c,%:
Sxn#
//打印回应的头信息 &356
public void logResponseHead(HttpURLConnection con) `TugtzRU
{ wOfx7D
for(int i=1;;i++) w4 R!aWLd
{ m6'VMW
String header=con.getHeaderFieldKey(i); ):LgZ4h
if(header!=null) "t[9EbFL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Zq,[se'nh"
Utility.log(header+" : "+con.getHeaderField(header)); R8Kj3wp
else pb>TUKvT&
break; &Nzq/~uqP
} b#h}g>l
} Wc6Jgpl
|$hBYw
6bv~E.
public void splitterStop() G[;GP0\N
{ >v sy P
bStop = true; n\X'2
} PTt#Ixn,
{>x6SVF
blUnAu o~
} EISgc {s
V*}xlxSL
3e)W_P*0?
/* bSG}I|
**FileAccess.java /Qa'\X,f3
*//文件访问(定位，写) O_gr{L}
package NetFox; pZVT:qFF
import java.io.*; .el&\Jt
xOKLc!J
x6h';W_ 8
public class FileAccessI implements Serializable{ Za"m;+H<E
X-lB1uq^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [Dzd39aKr
RandomAccessFile oSavedFile; j3W)
long nPos; \/wbk`2
-2D/RE7|
u0o}rA
public FileAccessI() throws IOException 6h?v/\
{ 80'!XKSP
this("",0); E]aQK.
} ?3duW$`
6I<^wS9j_
Ad:}i9-x
public FileAccessI(String sName,long nPos) throws IOException 0=:]tSD\F
{ 4\#b@1]}
oSavedFile = new RandomAccessFile(sName,"rw"); O ,9,=2j
this.nPos = nPos; dE_d.[!
oSavedFile.seek(nPos); I:l/U-b7h
} 7NFRCCXHQ
]Yw/}GKB
]ChGi[B~9
public synchronized int write(byte[] b,int nStart,int nLen) D#.N)@\
{ \>G:mMk/
int n = -1; \nzaF4+$
try{ ii)DOq#2
oSavedFile.write(b,nStart,nLen); ,UveH` n-
n = nLen; BH<jnQ
} 2[V9`r8*
catch(IOException e) qQ{i2D%)?f
{ VoGyjGt&
e.printStackTrace (); o-}q|tD$<
} =/Lwprj
L>ruNw'-K
_u]S/X-
return n; s(?A=JJ
} 4nz$Ja)
{F'~1qf
5ns.||%k
} jE#&u DfI
YCBcyE}p
GV"X) tGo
/* V,?BVt
**SiteInfoBean.java 6?(Z f
*/ PF+SHT'4}#
package NetFox; [ U`})
TIIwq H+h.
A`I;m0<
public class SiteInfoBean { 8Buus
`,7;2ZG~O
vNn$dc
private String sSiteURL; //Site's URL dBeZx1Dy
private String sFilePath; //Saved File's Path |bM?Q$>~
private String sFileName; //Saved File's Name Cvgk67C=$
private int nSplitter; //Count of Splited Downloading File y88lkV4a
DxvD 1u
-]-?>gkN5
public SiteInfoBean() `at>X&Ce,
{//nSplitter的缺省值为5 *ak"}s
//default value of nSplitter is 5 d^:(-2l-
this("","","",5); ?AlTQL~c
} )*m#RqLQ8
SmMJ%lgA6
713)D4y}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ixjhZki<
{ FG{45/0We
sSiteURL= sURL; `9vCl@"IV
sFilePath = sPath; WWtksi,
sFileName = sName; ([Da*Tk*
this.nSplitter = nSpiltter; h4,S/n
CY?19Ak-xd
:&-j{8p-
} VUbg{Rb)
k0>]7t$L
8)m
public String getSSiteURL() wF.S ,|
{ *D:"I!Ho
return sSiteURL; SQhw |QdG
} WvVf+|Km
Eq82?+9
B.ar!*X
public void setSSiteURL(String value) "l7))>lL
{ |\#6?y[o
sSiteURL = value; -6yFE- X/
} D/<;9hw
47 |&(,{
eNY?
public String getSFilePath() cpJ(77e
{ 5a^b{=#Y
return sFilePath; --'!5)U
} bKb}VP
><r\ 5`
x4e8;A(y
public void setSFilePath(String value) 4)OM58e}
{ a]%>7yr4
sFilePath = value; enw7?|(
} 3w!,@=.q
>ZjGs8&
C0#"U f
public String getSFileName() X ^\kI1
{ cfrvx^,2&
return sFileName; n1;y"`gHk
} &LM ^,xx}
r_EuLFMA
\NTNB9>CO
public void setSFileName(String value) #>[5NQ;$'
{ !tckE\ h#N
sFileName = value; 1XD|H_JG<j
} TxDzGC
g0M9v]c
5IfyD ]<
public int getNSplitter() 'du{ky
{ U%zZw)
return nSplitter; oHvVZ
} $9In\x
cpe/GvD5]
%$3)xtS6
public void setNSplitter(int nCount) Ix1[ $9
{ /'WIgP
nSplitter = nCount; )<8f3;qd
} $Eh8s(
} \UR/tlw+/
DAHQ7#qfQC
[pgld9To
/* ?=^M(TA;
**Utility.java H6! <y-
*/ iTpU4Qsj
package NetFox; <&Q(I+^
Ljq!\D
_5l3e7YN
public class Utility { xZpGSlA
%^VQw!
9p '#a:
public Utility() /:o (Ghc?
{ !5escR!\D
MDqUl:]
Qin;{8I0
} [bIR$c[G
S`v+rQjW
//线程睡眠 FaVeP%v
public static void sleep(int nSecond) 5Z@~d'D
{ 'D1Sm&M2%e
try{ :!nBTw
Thread.sleep(nSecond); QZ:xG:qyk;
} kV$$GLD\
catch(Exception e) WG\gf\=I
{ [WxRwE
e.printStackTrace (); ]Y%U5\$
} SK&?s`
} ulzQ[?OMl
^,;AM(E
//日志 $GcVI;a
public static void log(String sMsg) C6P(86?
{ |4tnG&=
System.err.println(sMsg); LG6k KG
} g3"eEg5NY
w\PCBY=
XnCrxj
public static void log(int sMsg) Js("H
{ ;?`l1:C5)
System.err.println(sMsg); ?5yj</W
} gY=Ry=w9
} JMa[Ulz
rDvz2p"R
v7kR]HU[y
/* sKLH.@
**TestMethod.java S7_^E
*/ ^3:y<{J
package NetFox; 5f'<0D;K
C"=^(HU
HvSYE[Zt|
public class TestMethod { Edi`x5"l
}[%d=NY
])YGeY(V0+
public TestMethod() YEB@p.
{ ///xx/weblogic60b2_win.exe :Ky *AI
try{ eJm7}\/6`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [Q+qu>&HB7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); RaNz)]+7`
SiteFileFetch fileFetch = new SiteFileFetch(bean); iNxuQ7~
fileFetch.start(); 6QC=:_M;
} 7KzMa%=
catch(Exception e){e.printStackTrace ();} `AO<r
8iDg2_l`G
-<0PBl
} Q:#Kt@W
V&>\U?q:
|y*-)t
public static void main(String[] args) *i>?YT
{ k5=VH5{S
new TestMethod(); V;V,G+0Re
} OSsxO(;g
} Qn*a#]p
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