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)); 1eZ759PoO
} VHlN;6Qlff
for(int i=0;i<nEndPos.length-1;i++) Oa'DVfw2J
{ ,L"1Ah
nEndPos = nStartPos[i+1]; h!L/ZeRaV
} w<ol$2&B
nEndPos[nEndPos.length-1] = nFileLength; m*d {pX
} $bd&$@sA
} azxGUS_i<
JAK+v
f2JeXsOI
//启动子线程 cq=ker zQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Nx8~Rn
for(int i=0;i<nStartPos.length;i++) ~P47:IZf
{ QD}'2{M!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \NEXtr`Th
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), SeC[,
nStartPos,nEndPos,i); 1$*ZN4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "0(H! }D
fileSplitterFetch.start(); Vu/{Hr
} <&+\X6w[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,p,$(V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J\BTrN7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;e>pu"#
nEndPos = " + nFileLength); hw@ `Q@
// fileSplitterFetch[nPos.length-1].start(); e7(iMe
6Ch [!=p{
DO#!ce
//等待子线程结束 D[7+xAwS
//int count = 0; )NoNgU\7!
//是否结束while循环 R3;,EL{H&
boolean breakWhile = false; J m5).
fR&;E
6,707h
while(!bStop) b6FC
{ `n*e8T
write_nPos(); <Oi65O_X
Utility.sleep(500); %q~YJ*\
breakWhile = true; e-Xr^@M*Q
=peodj^
fr\"MP
for(int i=0;i<nStartPos.length;i++) Qd %U(|
{ w$X"E*~>8
if(!fileSplitterFetch.bDownOver) DcO$&)Eb
{ Y-Zw'
breakWhile = false; L*Gk1'
break; wN|;_~h2
} T=EHue$
} `Dck$
if(breakWhile) DHUK_#!
break; |#_F
'UYxVh9D
%yjz@
//count++; 5 (Lw-_y#
//if(count>4) _</>`P[
// siteStop(); *kmD/J
} \i*QKV<
i;u#<y{E
*Vbf;=Mb
System.err.println("文件下载结束！"); >tmv3_<=
} A)2eo<ij4
catch(Exception e){e.printStackTrace ();} Ej\Me
} k$kOp *X
4@iMGYR9!s
=N62 ){{
//获得文件长度 e ej:
public long getFileSize() lo1<t<w`
{ D#=$? {w
int nFileLength = -1; }#u.Of`6"
try{ b6`_;Z
URL url = new URL(siteInfoBean.getSSiteURL()); =RA8^wI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D%=VhKq
httpConnection.setRequestProperty("User-Agent","NetFox"); B_gzpS]
kqebU!0-
lUL6L4m
int responseCode=httpConnection.getResponseCode(); mW/6FC
if(responseCode>=400) [MQU~+]
{ eHQS\n
processErrorCode(responseCode); t",=]k
return -2; //-2 represent access is error iI!MF1
} f,jN"
\jkMnS6FvL
?06+"Z
String sHeader; SBf8Ipe
9!``~]G2
x1@`\r#0
for(int i=1;;i++) u8w4e!rKo6
{ `X["Bgk$!T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %kHeU=
//Utility.log(in.readLine()); 0eGz|J*7
sHeader=httpConnection.getHeaderFieldKey(i); ;?{N=x8
if(sHeader!=null) *%3%Zj,{
{ IL]Js W
if(sHeader.equals("Content-Length")) #j+0jFu
{ 8|z@"b l)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lU`}
break; {RmN1'%
} ;JD/4:
} lYF~CNvE
else m@Q%)sc)
break; d)R7#HLZ7
} CeZ+!-lG
} Y"n$d0%
catch(IOException e){e.printStackTrace ();} 1edeV48{:
catch(Exception e){e.printStackTrace ();} IO@Ti(,
0SHF 8kek
z]twh&^1L
Utility.log(nFileLength); TtWE:xE
6h5,XcO4
0b)q,]l]
return nFileLength; 5DI&pR1eZ
} <>Nq]WqA
?oD]J
mRECdGst
//保存下载信息（文件指针位置） 6EX_IDb
private void write_nPos() NwISf
{ i$z).S?1
try{ ^$D2fS
output = new DataOutputStream(new FileOutputStream(tmpFile)); /c&;WlE/n
output.writeInt(nStartPos.length); r(VGdG
for(int i=0;i<nStartPos.length;i++) |z+K]R8_
{ sTb@nrRxH
// output.writeLong(nPos); oEuV&m|yX
output.writeLong(fileSplitterFetch.nStartPos); :L6,=#
output.writeLong(fileSplitterFetch.nEndPos); ru#CywK{{;
} b9%G"?~Zz
output.close(); X!AD]sK
} DNyU]+\L[l
catch(IOException e){e.printStackTrace ();} >Oz~j>jL
catch(Exception e){e.printStackTrace ();} ?BEO(;'
} xoYaL
U WU PY
3G.-JLhs
//读取保存的下载信息（文件指针位置） s|O4>LsG
private void read_nPos() <5xlP:Cx
{ eyIbjgpV
try{ PCcI(b>?l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -Wt(t2
int nCount = input.readInt(); ?xT ^9
nStartPos = new long[nCount]; sN8)p%'Lg
nEndPos = new long[nCount]; >T)#KQ1t
for(int i=0;i<nStartPos.length;i++) *#| lhf'
{ VGVb3@
nStartPos = input.readLong(); ?r%kif)
nEndPos = input.readLong(); :~ ; 48m
} H6vO}pq)r
input.close(); 6+iZJgwAy
} k^:+Pp
catch(IOException e){e.printStackTrace ();} &~ .n}h&
catch(Exception e){e.printStackTrace ();} 2Sha&Z*CE
} K]Rb~+a<
?kBX:(g
X%lk] &2
private void processErrorCode(int nErrorCode) ]iHSUP
{ xV+cX*4h
System.err.println("Error Code : " + nErrorCode); V-N`R-FSr
} 1oSU>I_i
|{j\7G*5
{I9<W'k{
//停止文件下载 ro8c-[V
public void siteStop() GX@=b6#-
{ LV6BSQyQ
bStop = true; ^*@D%U
for(int i=0;i<nStartPos.length;i++) G,,7.%eib=
fileSplitterFetch.splitterStop(); UVlXDebl
6z3`*B
!hc#il'g].
} _]"uq/UWp
} q Xj]O3 mm
//负责部分文件的抓取 ?Dn 6
**FileSplitterFetch.java k "Qr
*/ j3$\+<m]
package NetFox; Ae3=o8p
Pg%k>~i
3$#=*Zp
import java.io.*; +j!$88%Z{
import java.net.*; $Ao iH{f
&XF@Dvv
|-zefzD|
public class FileSplitterFetch extends Thread { {@*l,[,5-
rIRkXO)
'6zk>rN
String sURL; //File URL ^a#
long nStartPos; //File Snippet Start Position U_oei3QP
long nEndPos; //File Snippet End Position CeD(!1VG
int nThreadID; //Thread's ID k>W}9^ cK
boolean bDownOver = false; //Downing is over Q!`
boolean bStop = false; //Stop identical !`S61~gE
FileAccessI fileAccessI = null; //File Access interface X6SqOb\(a
{u@w^ hZ$
O[|prk,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i^_?C5
{ h5p,BRtu
this.sURL = sURL; `ZELw=kLL
this.nStartPos = nStart; rpn&.#KS
this.nEndPos = nEnd; -D^.I
nThreadID = id; +|c1G[Jh
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K=Y{iHn
} ~H\1dCW
=Dc9|WuHN
C[2LP$6*/
public void run() vWq/A.
{ GW~ZmK
while(nStartPos < nEndPos && !bStop) s&Lyg>>`
{ w7"&\8a
$geDB~ 2>
nZP%Z=p7
try{ 2y` :#e`x1
URL url = new URL(sURL); 9Lp[y%{GP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FF'Ul4y
httpConnection.setRequestProperty("User-Agent","NetFox"); Q2jl61d_9
String sProperty = "bytes="+nStartPos+"-"; .~Y% AI
httpConnection.setRequestProperty("RANGE",sProperty); r;'Vy0?AL
Utility.log(sProperty); 1Uf8ef1,
m>8tA+K)+)
.N~YVul[a*
InputStream input = httpConnection.getInputStream(); 6SVh6o@]
//logResponseHead(httpConnection); {cMf_qQ
r]yI5 ;
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byte[] b = new byte[1024]; oaMh5FPy
int nRead; P d)<Iw^<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;UoXj+Z
{ F?.J1]
nStartPos += fileAccessI.write(b,0,nRead); g6l&;S40
//if(nThreadID == 1) q%\rj?U_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jdW#; ]7+y
} V(6GM+
u.R
_^Yav.A=
Utility.log("Thread " + nThreadID + " is over!"); y - Ge"mY
bDownOver = true; ; +%|!~
//nPos = fileAccessI.write (b,0,nRead); ]~J.YX9ST
} Qu6Q)dZ<
catch(Exception e){e.printStackTrace ();} u8sK~1CPf
} 3oE3bBj
} :j4i(qcF
q A?j-H
01AzM)U3"m
//打印回应的头信息 DY'1#$;
public void logResponseHead(HttpURLConnection con) * u{CnH
{ BzyzOtBp3L
for(int i=1;;i++) 0$e]?]X6
{ y+K21(z.
String header=con.getHeaderFieldKey(i); EWn\]f|
if(header!=null) <h<4R Rj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B%^ $fJ|
Utility.log(header+" : "+con.getHeaderField(header)); ]xf|xs
else ,.PW qfb
break; zm`^=cV
} {xS\CC(g
} #M5[TN!
.X(*mmH
DX)T}V&mP
public void splitterStop() Z2soy-
{ &]euL:C
bStop = true; \5=fC9*G
} 'l`T(_zL\%
+jIE,N
q)E J?-
} y*fU_Il|!
`Z!NOC
J^]Y`Q`
/* FdVWj 5 $a
**FileAccess.java +5C*i@v
*//文件访问(定位，写) )Og,VXEB
package NetFox; '@Q aeFm
import java.io.*; M+q|z0U
]'a9>o
_m8JU
public class FileAccessI implements Serializable{ *q/oS8vavd
v\gCgx=%j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -+#g.1UL/
RandomAccessFile oSavedFile; 7<?~A6
long nPos; tzFgPeo$;
b6E,u*)"
B\z4o\am%
public FileAccessI() throws IOException SOPQg?'n=V
{ %`Q<_LTU
this("",0); -A A='s
} Axtf,x+lH
,0=@cJ
3"OD"
public FileAccessI(String sName,long nPos) throws IOException B U^3Ux$
{ ,'69RL?-Wg
oSavedFile = new RandomAccessFile(sName,"rw"); u teI[Q
this.nPos = nPos; (&x#VmDL
oSavedFile.seek(nPos); K[(h2&
} &v#*
#[a+m
1*!`G5c,}
public synchronized int write(byte[] b,int nStart,int nLen) {Noa4i
{ ua-cX3E
int n = -1; WV'FW)%
try{ G()- NJ{
oSavedFile.write(b,nStart,nLen); aH1mW;,1u
n = nLen; fGD#|a;,
} b1A8 -![
catch(IOException e) Zk.LGYz
{ 'nFqq:2Xa
e.printStackTrace (); ZJxUv {J
} (|PxR#{l<
%kg%ttu7
7TC=$y ,
return n; O)tZ`X;
} >/DyR+?>4
2@ <x%T
8R6!SB
} JRC+>'}Xj
}"'^.FG^_
yn[^!GuJ_
/* |W/_S^C
**SiteInfoBean.java ci@U a}T
*/ m-Uq6_e
package NetFox; LI&+5`
o!3-=<^
YAIDSZ&l[
public class SiteInfoBean { +##b}?S%
&.Jp,Xt)
H?P:;1A]c
private String sSiteURL; //Site's URL C NNyz$
private String sFilePath; //Saved File's Path mGXjSWsd
private String sFileName; //Saved File's Name ^]$x/1I;
private int nSplitter; //Count of Splited Downloading File wv2
( *(#;|m
^fLePsmd
public SiteInfoBean() J/j?;qx]j
{//nSplitter的缺省值为5 Xw=>L#Q
//default value of nSplitter is 5 R18jju>Zr
this("","","",5); ov=[g l
} Fvy__qcHi
n0T\dc~
u(7PtmV[!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @}K'Ic
{ McgTTM;E
sSiteURL= sURL; %r0yBK2uOp
sFilePath = sPath; _91g=pM
sFileName = sName; !po8[fz~x
this.nSplitter = nSpiltter; <|M cE
0@yHT-Dy
J>YwMl
} !79^M
8Vkw vc
gsn3]^X
public String getSSiteURL() :t6w+h
{ 5'/Ney9N
return sSiteURL; SsDe\"?Q
} ThX%Uzd"[;
?v>!wuiP
M ]dS>W%U
public void setSSiteURL(String value) {q%wr*
{ b8QA>]6A
sSiteURL = value; %pNK ?M+
} !_VKJZuH
Lt+ Cm$3
ngprTMO$&
public String getSFilePath() h&+dIk\[3
{ Ji_3*(
return sFilePath; 3[E3]]OVa
} OAMsqeWYA
{$,e@nn
9Xt5{\PJ
public void setSFilePath(String value) ErK5iTSD
{ -aDGXQM{~
sFilePath = value; u%<Je
} ty|E[Ez1
Ll%CeP
5Xu2MY=
public String getSFileName() %nQii?1`i
{ c(.2D
return sFileName; wRn]
} [];*9vxW
VLuhURI)
>(s)S[\
public void setSFileName(String value) 31\l0Jg
{ :b[ [}'
sFileName = value; 8<Cu S
} 5:%xuJD
37DyDzW)'
5A,@$yp+
public int getNSplitter() sas}k7m"
{ 7*8R:X+^r
return nSplitter; m$ZPQ0X
} @UCGsw
=7@N'xX
{ZiJnJX
public void setNSplitter(int nCount) *2ZX*w37
{ /s"mqBXCG
nSplitter = nCount; w yP|#Z\
} rmS.$h@7 m
} n`Pwo&
HV-c DL
eAh~`
/* `LU[+F8<
**Utility.java Eg&xIyRmm
*/ -&JUg o=
package NetFox; ;LRY h?
S"ZH5O(
JsohhkJNGi
public class Utility { U}ei2q\
F.2<G.9
G.Z:00x
public Utility() _KBN
{ BbEWa
"c8 -xG
T 22tZp
} yOwo(+ 2
Umx~!YL!
//线程睡眠 hh/C{ l
public static void sleep(int nSecond) kH'LG!O
{ I8;xuutc
try{ QOA7#H-m9
Thread.sleep(nSecond); `)Z"||8K
} J jRz<T;
catch(Exception e) f%fD>a
{ `yYoVu*
e.printStackTrace (); U.]5UP:a
} JDcc`&`M
} e 4-
#9-qF9M
//日志 u~WBu|
public static void log(String sMsg) npC:SrI%
{ FCL7Tn
System.err.println(sMsg); &)[?D<
} N>kY$*
1h uU7xuf
THC7e>P4
public static void log(int sMsg) G`H4#@]
{ "M#A `b
System.err.println(sMsg); jdz]+Q`jq
} GCaiogiBg
} }+/j/es{]
9u6GeK~G
jcrLUs+\
/* Jg} w{,
**TestMethod.java 'sb&xj`d
*/ O# n<`;W
package NetFox; !C13E lf
ZfMDyS$.
{m%]`0
public class TestMethod { }7?n\I+n"
P1cI]rriW
?'>pfU
public TestMethod() 9)P-<
{ ///xx/weblogic60b2_win.exe #aHPB#
try{ }eKY%WU>O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Tvp~~Dk
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d\c?sYLv
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3|++2Z{},
fileFetch.start(); |E]`rfr
} 73C7g< Mx
catch(Exception e){e.printStackTrace ();} M N-j$-y}
Sq<ds}o'8l
;og[q
} olA 1,8
m2sf]-?Y
^@91BY
public static void main(String[] args) Hs9; &C
{ {"rYlN7,
new TestMethod(); {&u`d.Lk2p
} 2!@ER i
} hYvWD.c}
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