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)); ee5QZ,
} 8`j;v>2
for(int i=0;i<nEndPos.length-1;i++) DGllJ_/Z
{ u%`4;|tI
nEndPos = nStartPos[i+1]; S/l?wwD
} \JX.)&> -
nEndPos[nEndPos.length-1] = nFileLength; P0N%77p>"
} 2~BId&]
} 3cztMi
?]bZ6|;2
%}%vey
//启动子线程 d,0Yi u.p
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r\sQ8/
for(int i=0;i<nStartPos.length;i++) k2S6 SB
{ MX.=k>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !Qd4Y=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lY_&P.B
nStartPos,nEndPos,i); ZZXQCP6]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <O#/-r>2
fileSplitterFetch.start(); 1]lm0bfs
} |(=`l
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .5PcprE/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ixFuqPij
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &%/kPF~<
nEndPos = " + nFileLength); ;v?!Pml2k
// fileSplitterFetch[nPos.length-1].start(); Y)=89s&t
E'J| p7
I8 \Ka=w
//等待子线程结束 aykNH>#Po
//int count = 0; k_c8\::p#
//是否结束while循环 +R_w- NI
boolean breakWhile = false; ^KsiTVY
5YG?m{hyn_
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while(!bStop) Y:0SrB!\
{ z7H[\4A!>
write_nPos(); b6k'`vLA
Utility.sleep(500); v!pT!(h4
breakWhile = true; p^U:O&U(
2@ <x%T
8R6!SB
for(int i=0;i<nStartPos.length;i++) .d;XLS~
{ K] ^kUN_
if(!fileSplitterFetch.bDownOver) Rj|8lK;,
{ #.(6.Li
breakWhile = false; 3PEv.hGx
break; P"<HxT?
} Xh,{/5m
} 9W{=6D86e
if(breakWhile) Vc!;O9dP
break; pOCLyM9c
wv2
1>"K<6b+
//count++; 5Z7<X2
//if(count>4) pv=g)
// siteStop(); /hef3DV5I
} D! 1oYr
@}K'Ic
_U.D*f<3)
System.err.println("文件下载结束！"); ag-\(i;K]
} T<|B1jA
catch(Exception e){e.printStackTrace ();} `5:Wv b>|
} ^1vh5D
oyBBW?m
ZkW,
//获得文件长度 X=Q)R1~6v
public long getFileSize() Y. ]FVq
{ /HsJyp+t
int nFileLength = -1; krPwFp2[*
try{ ;^}gC}tq
URL url = new URL(siteInfoBean.getSSiteURL()); _-&\~w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ji_3*(
httpConnection.setRequestProperty("User-Agent","NetFox"); J~6+zBF
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]A:n]mL
int responseCode=httpConnection.getResponseCode(); TC80nP
if(responseCode>=400) XO+^q9
{ 'ao<gTUbu
processErrorCode(responseCode); sv0)sL
return -2; //-2 represent access is error \`\& G-\
} [];*9vxW
%O`e!p
sr+* q6W
String sHeader; V,<3uQD9a
t@[&8j2B>
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for(int i=1;;i++) 7*8R:X+^r
{ a9C8Q l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *Ppb;
//Utility.log(in.readLine()); sK8=PZ\
sHeader=httpConnection.getHeaderFieldKey(i); +jePp_3$O
if(sHeader!=null) HV-c DL
{ j:# wt70
if(sHeader.equals("Content-Length")) B#Cb`b"
{ g5X;]%:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,U+y)w]ar
break; 1'or[Os3=
} j+He8w-4
} u}ULb F
else wQ /IT}-
break; P` Hxj> {
} Q>Rjv.1
} %UDz4?zx
catch(IOException e){e.printStackTrace ();} ;i*<HNQ
catch(Exception e){e.printStackTrace ();} 7\>P@s
EkotVzR5
d[mmwgSR?I
Utility.log(nFileLength); e P]L
xE.K
qdkhfm2(K
return nFileLength; 'B dZN
} )Qe<XJH!
%M8m 8 )
\ng!qN
//保存下载信息（文件指针位置） Fk(nf9M%
private void write_nPos() 28,Hd!{
{ m)l<2`CM
try{ 1t&LNIc|^
output = new DataOutputStream(new FileOutputStream(tmpFile)); RCM;k;@8V
output.writeInt(nStartPos.length); kr ,&aP<,
for(int i=0;i<nStartPos.length;i++) /Kcp9Qx
{ >&pB&'A a
// output.writeLong(nPos); :;Z?2P5i
output.writeLong(fileSplitterFetch.nStartPos); Cngi5._Lb
output.writeLong(fileSplitterFetch.nEndPos); = BcKWC
} L@9@3?
output.close(); vmEbk/Vy
} 8EbJ5wu/%S
catch(IOException e){e.printStackTrace ();} BwpEIV@b]
catch(Exception e){e.printStackTrace ();} 2F5*C
} C_CUk d[
1eod;^AP9
okwkMd-yW
//读取保存的下载信息（文件指针位置） ,xcm:;&
private void read_nPos() `Hlv*" w$
{ KZeaM
try{ M N-j$-y}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +95: O 8
int nCount = input.readInt(); h"#[{$(
nStartPos = new long[nCount]; 0eJqDCmH
nEndPos = new long[nCount]; su2|x
for(int i=0;i<nStartPos.length;i++) =74yhPAW
{ 6KH&-ffd
nStartPos = input.readLong(); +K2p2Dw(k
nEndPos = input.readLong(); X(r$OZ
} tJ3Hg8;
input.close(); L0^rw|Z%'
} }#cFr)4f
catch(IOException e){e.printStackTrace ();} T)CEcz
catch(Exception e){e.printStackTrace ();} }Bk>'
} cc0e(\
$u"*n\k>
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private void processErrorCode(int nErrorCode) wC&+nS1
{ A#;TY:D2
System.err.println("Error Code : " + nErrorCode); w^EUBRI-
} dj}y6V&
s[dq-pc"
.\rJ|HpZ1J
//停止文件下载 c.?+rcnq
public void siteStop() W)LtnD2 w
{ d,V]j-
bStop = true; paYvYK-K?
for(int i=0;i<nStartPos.length;i++) 8+|7*Ud
fileSplitterFetch.splitterStop(); EJByYk
=@\Li)Y
#cCR\$-~
} x2M{=MExE.
} Y I?4e7Z+
//负责部分文件的抓取 b^dBX
**FileSplitterFetch.java KQulz
*/ +Rq7m]
package NetFox; <c!I\y
Jc9BZ`~i
_/pdZM,V
import java.io.*; gPf^dGi7t
import java.net.*; K/A1g.$
kf-/rC)>
j"Y5j B`
public class FileSplitterFetch extends Thread { d{FD.eI0
>XU93 )CX
@\)a&p]a
String sURL; //File URL }'c@E0"
long nStartPos; //File Snippet Start Position z@tIC^s
long nEndPos; //File Snippet End Position y&(R1Y75
int nThreadID; //Thread's ID m2r%m y
boolean bDownOver = false; //Downing is over 41s[p56+@
boolean bStop = false; //Stop identical *nYb9.T]i
FileAccessI fileAccessI = null; //File Access interface O8<@+xlX
2E/yZ ~2s
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o4d[LV4DS
{ $g@-WNe
this.sURL = sURL; xA#'%|"
this.nStartPos = nStart; gU%R9
this.nEndPos = nEnd; fs3jPHZJ#
nThreadID = id; }DzN-g<K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1 GB
} \EC7*a0
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mEVne.D
public void run() Q"D%xY
{ M].D27
while(nStartPos < nEndPos && !bStop) ?]Z EK8c
{ ?cmv;KV
F qH@iZ
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try{ 'boAv%1_sa
URL url = new URL(sURL); nv-_\M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FZJyqqA$_
httpConnection.setRequestProperty("User-Agent","NetFox"); `mo>~c7
String sProperty = "bytes="+nStartPos+"-"; m=e#1Hs
httpConnection.setRequestProperty("RANGE",sProperty); h"849c;C.
Utility.log(sProperty); bR&<vrMmrA
AOVoOd+6
t^(#~hx
InputStream input = httpConnection.getInputStream(); o ImW
//logResponseHead(httpConnection); _>)=c<HL
W*D].|
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byte[] b = new byte[1024]; /`YbHYNF[
int nRead; _!'sj=n]q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ab-MEN`5
{ ja|XFs~
nStartPos += fileAccessI.write(b,0,nRead); J"W+9sI0
//if(nThreadID == 1) jy2@t*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $v*0\O
} *iW$>Yjb
#&jr9RB
W;9Jah.
Utility.log("Thread " + nThreadID + " is over!"); Q`4]\)Dp
bDownOver = true; DJ#z0)3<p
//nPos = fileAccessI.write (b,0,nRead); TR([u
} ;N/=)m
catch(Exception e){e.printStackTrace ();} OJH:k~]0!
} QW_QizR>|
} B,dHhwO*l
Z" !+p{u
[ queXDn"m
//打印回应的头信息 iTq~^9G
public void logResponseHead(HttpURLConnection con) _U@;Z*(%vh
{ 8*V8B=q}K
for(int i=1;;i++) LN?b6s75U
{ 3M&IMf,/@
String header=con.getHeaderFieldKey(i); `Wf)qMb
if(header!=null) m#oZu {
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [!v| M
Utility.log(header+" : "+con.getHeaderField(header)); ecI[lB
else ^9Je8 @Yu
break; 4gNF;
} \I4*|6kA
} 7v~\c%1V
G)E#wh_S^
Y_)aoRjB
public void splitterStop() {=NHidi~
{ 5_mb+A n,
bStop = true; 1Jx|0YmO
} Kb#}f/
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Ye8&cZ*.
} sDH|k@K
Hkv4t5F
L|3wGY9E
/* ?q%)8 E
**FileAccess.java uT}Jw
*//文件访问(定位，写) | ZI~#V
package NetFox; g8{?;
import java.io.*; E&/D%}Wl
(zFUC]
gJyFt8Z<
public class FileAccessI implements Serializable{ ='7n
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//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .bm#|X)RO
RandomAccessFile oSavedFile; l_!.yV{
long nPos; KJwkkCE/=
I]`>m3SJ
~[i,f0O,
public FileAccessI() throws IOException CMIjc(m
{ PUUBn"U-
this("",0); 9GdrJ~h
} S!GjCog^J
'U)|m
#pxc6W /
public FileAccessI(String sName,long nPos) throws IOException @5%cP
{ !P, 9Sg&5)
oSavedFile = new RandomAccessFile(sName,"rw"); / 4K*iq
this.nPos = nPos; EX[X|"r
oSavedFile.seek(nPos); >a]4}
} 1:%m >4U
d0b--v/
62}bs/%
public synchronized int write(byte[] b,int nStart,int nLen) &Z+a (
{ )>ed6A1
int n = -1; [|2uu."$
try{ HRx%m1H
oSavedFile.write(b,nStart,nLen); BEM+FG
n = nLen; 'nNw
} :5@cjj
catch(IOException e) %>uGzQ61
{ j\nnx8`7
e.printStackTrace (); RGGP6SDc
} ^c1I'9(r5
#ZIV>(Q\H
N1Y*IkW"
return n; VwoCRq*
} (~TP
$2F*p#l(<Z
>R?EJ;h
} $7aRf'
{=7W;uL
Y.yM1 z
/* PZO7eEt8
**SiteInfoBean.java Z{/C4" F
*/ F'Fc)9qFa<
package NetFox; \1RQ),5 %]
:Qu!0tY
3Fh<%<=
public class SiteInfoBean { "HVwm>qEi
K+H?,I
hE!3kaS
private String sSiteURL; //Site's URL `NV =2T
private String sFilePath; //Saved File's Path [*?P2.bf
private String sFileName; //Saved File's Name %yQ-~T@
private int nSplitter; //Count of Splited Downloading File lw? f2_fi
/w!b2KwV
Bl'
public SiteInfoBean() G4s!q1H
{//nSplitter的缺省值为5 bqf=;Nvog
//default value of nSplitter is 5 &}w,bG$
this("","","",5); [_qBp:_j?s
} 6%ID*
>Q+a'bd w
^F`FB..:y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) D2>EG~xWq
{ 'y}A3RqN
sSiteURL= sURL; *D;B%j^;
sFilePath = sPath; Bi kCjP[b
sFileName = sName; 7=T0Sa*;
this.nSplitter = nSpiltter; &66G
x`%;Q@G
sj. eJX"z
} ]$nJn+85@b
3=dGz^Zdv:
EE&~D~yHUL
public String getSSiteURL() &.7\{q\(
{ FPFt3XL
return sSiteURL; pPh_p@3I
} )KBv[|
sTv/;*
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public void setSSiteURL(String value) Ylt[Ks<2
{ l*'jqR')h^
sSiteURL = value; f 21w`Uk48
} _E'M(.B<
ej%C<0/%n
c q3CN@
public String getSFilePath() 30<dEoF
{ T X6Ydd
return sFilePath; %iD>^Dp
} >454Yir0Mk
:?RK>}4|F
tinN$o Xy
public void setSFilePath(String value) #llc5i;
{ fEQ<L!'
sFilePath = value; Vaq=f/
} SC|cCK hqi
1uXtBk6
_/E>38G]
public String getSFileName() 'a"<uk3DT
{ D;d;:WT5
return sFileName; iNQk{n
} z9dVT'
j*xens$)
+p<Y)Z(>6
public void setSFileName(String value) lc5NC;JR
{ WUa-hm2:
sFileName = value; bjQfZT(
} n:<avl@o<
5@Py`
h{PLyWH
public int getNSplitter() rSEJ2%iF*
{ Ip2JzE
return nSplitter; >eUAHmXQ|
} d[$1:V
d1E~H]X4
`DA=';>Y
public void setNSplitter(int nCount) C)ChF`Ru':
{ Rwy:.)7B$q
nSplitter = nCount; hF2 G{{8A
} RNt3az
} ^NnZYr.
E RMh% C
Y":hb;&
/* $x2<D :
**Utility.java b?y1cxTT
*/ _`D_0v(X
package NetFox; ~O^_J)
j5/H#_.
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public class Utility { {u5)zVYC,U
mGY74>/
_@RW7iP>
public Utility() \+>b W(
{ g@EKJFjl
f,uxoAS
.g|pgFM?
} ev@1+7(
p,1RRbyc
//线程睡眠 tx.YW9xD
public static void sleep(int nSecond) )1]C%)zn
{ >i ~zG6H
try{ vu#:D1/BB
Thread.sleep(nSecond); }=L >u>cP
} #Gg^fm
catch(Exception e) VtmUK$k}I
{ HmiwpI
e.printStackTrace (); AV&ege
} x*)Wl!
} 4t+88e
|zUDu\MZ{
//日志 |Y99s)2&N
public static void log(String sMsg) ]pGr'T~Gj
{ Ln: y|t
System.err.println(sMsg); v>e4a/
} I2/wu(~>
f2Slsl;
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public static void log(int sMsg) ov+qYBuFw
{ 8<G@s`*
System.err.println(sMsg); KA<
} <zUmcZ
} z/TZOFaM
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/* aL`pvsnF
**TestMethod.java mB :lp=c`
*/ xpnnWHdaq
package NetFox; p$=3&qR 6
+Q '|->#
%DN&K
public class TestMethod { ?|L)!LYx
V&>7i9lEz
$@NZ*m%?JQ
public TestMethod() *kIJv?%_}
{ ///xx/weblogic60b2_win.exe *rbH|o8
try{ Gmwn:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H;CGLis
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B%t^QbU#\
SiteFileFetch fileFetch = new SiteFileFetch(bean); Fivv#4YO
fileFetch.start(); 1zM`g_(#
} 9UwDa`^
catch(Exception e){e.printStackTrace ();} eMF%!qUr
$`Ou*
l^vq'<kI
} wVPq1? 9
LY|h*a6Ym
J^W.TM&q$,
public static void main(String[] args) 1idEm*3&(
{ AV'>
new TestMethod(); jy*wj7fj1
} tsk}]@W
} QL)UPf>Kp
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