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)); FFX-kS
} 0=O(+ yi
for(int i=0;i<nEndPos.length-1;i++) wd*8w$\
{ +A%|.;
nEndPos = nStartPos[i+1]; + 2v6fan
} 15dhr]8E
nEndPos[nEndPos.length-1] = nFileLength; Yci>'$tQ
} Ey96XJV
} F|pM$Kd`
2*;qr|h,
$2uk;&"?A=
//启动子线程 @i2"+_}*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y1fcp_]m
for(int i=0;i<nStartPos.length;i++) kT)[<`p
{ V&)Jvx}^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v6=pV4k9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M|8vP53=q
nStartPos,nEndPos,i); 4FrP%|%E~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8*o*?1.
fileSplitterFetch.start(); GPV=(}z
} &iKy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =`Ii?xo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "i>?Tg^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l@:Tw.+/9
nEndPos = " + nFileLength); E$l4v>iA
// fileSplitterFetch[nPos.length-1].start(); #C^)W/dP
@A32|p}
fk%W07x!
//等待子线程结束 1OI/!!t1$
//int count = 0; .5$"qb ?
//是否结束while循环 J]G] <)
boolean breakWhile = false; I<E~=
;IyA"C(i
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while(!bStop) }@6Tcn1
{ D!7-(3R
write_nPos(); 6[+@#IWx
Utility.sleep(500); @7S* ]
breakWhile = true; qFQO1"mu
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for(int i=0;i<nStartPos.length;i++) r~rftw
{ 7m.#No>^
if(!fileSplitterFetch.bDownOver) yuP1*QJ%
{ 1N\/61+aA
breakWhile = false; l9{}nz
break; P=3mLz-
} T.d1?
} ,f*Q3 S/I
if(breakWhile) 7b8+"5~
break; 2F7(Y)
M02U,!di
Q Ev7k
//count++; $'*q]]
//if(count>4) B^;"<2b*
// siteStop(); +/+>:
} P;8nC:zL
e|-&h `[
3uXRS,C
System.err.println("文件下载结束！"); Nyx)&T&I
} *jQ?(Tf
catch(Exception e){e.printStackTrace ();} (>.lkR
} z]+&kNm
X,xCR]+5S
^cDHC^Wm
//获得文件长度 j_3`J8WwF
public long getFileSize() hs^K9Jt
{ WUBI(g\
int nFileLength = -1; :+ZLKm
try{ 8 $qj&2 N
URL url = new URL(siteInfoBean.getSSiteURL()); xeNj@\jdC5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NHaY&\
httpConnection.setRequestProperty("User-Agent","NetFox"); G)8v~=Bv
T W#s)iDi
{ )g $
int responseCode=httpConnection.getResponseCode(); S(^HIJK
if(responseCode>=400) MCO2(E-
{ ,ZV>"'I:
processErrorCode(responseCode); ?lca#@f(
return -2; //-2 represent access is error AZ.$g?3w
} WAt=T3
-I?8\
I+{2DY/}
String sHeader; WQ+ xS!ba
CK+t6Gp
xlcL;e&^P
for(int i=1;;i++) x^zw1e,y
{ ;\g0*b(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "5HSCl$r%
//Utility.log(in.readLine()); oRZ98?Y\B
sHeader=httpConnection.getHeaderFieldKey(i); "wy2u~
if(sHeader!=null) j:2TicHDC
{ [KL-T16
if(sHeader.equals("Content-Length")) j-cp
{ 5,R4:y ?cK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?}e^-//*i
break; Kn=0AdM
} w,i?e\5
} =&i#NSK
else i!{A7mo
break; s(T0lul
} !,|-{":
} eo*l^7
catch(IOException e){e.printStackTrace ();} 72CHyl`|l
catch(Exception e){e.printStackTrace ();} mBeP"GS
t"s$YB>}
9:E:3%%
Utility.log(nFileLength); xtBu]I)%
?W>`skQ
@<.ei)cqb
return nFileLength; IeZ9 "o h
} u69UUkG
{/j gB"9
R<B5<!+
//保存下载信息（文件指针位置） esiU._:u
private void write_nPos() D0Mxl?S?
{ &,P; 7R
try{ a&2UDl%K
output = new DataOutputStream(new FileOutputStream(tmpFile)); I_m3|VCa|t
output.writeInt(nStartPos.length); 5Gs>rq" #
for(int i=0;i<nStartPos.length;i++) [D+,I1u2h
{ fGd1
// output.writeLong(nPos); ppo0DC\>
output.writeLong(fileSplitterFetch.nStartPos); 9 JhCSw-<)
output.writeLong(fileSplitterFetch.nEndPos); u`ryCZo#g
} k;B[wEW@
output.close(); ]$uC~b
} + ZKU2N*
catch(IOException e){e.printStackTrace ();} jOU99X\0
catch(Exception e){e.printStackTrace ();} ;X^#$*=Q
} OxPl0-]t
&) 64:l&
&:&~[4>%a
//读取保存的下载信息（文件指针位置） @j!(at4B
private void read_nPos() 4fIjVx
{ >8ryA$
try{ 'QQq0.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xG;;ykh.]
int nCount = input.readInt(); P!"{-m'
nStartPos = new long[nCount]; Q*Y-@lZ
nEndPos = new long[nCount]; :c|Om{;
for(int i=0;i<nStartPos.length;i++) GM8Q#vc
{ 02tt.0go
nStartPos = input.readLong(); Wco2i m
nEndPos = input.readLong(); *MS$C$HOq
} r.'xqzF/
input.close(); @ x .`z
} ;Xf1BG r
catch(IOException e){e.printStackTrace ();} c`/VYgcTqB
catch(Exception e){e.printStackTrace ();} soLW'8
} q9dplEe5
{i+ o'Lw
s=]NKJaQH
private void processErrorCode(int nErrorCode) HUMy\u84H
{ gV-*z}`U
System.err.println("Error Code : " + nErrorCode); q1q9W@H
} gs3c1Qa3b
pSbtm74
fgs@oaoZ
//停止文件下载 o5j6(`#;
public void siteStop() I(Qz%/Ox
{ c9G%;U)
bStop = true; (5@H<c^6
for(int i=0;i<nStartPos.length;i++) X0iy
fileSplitterFetch.splitterStop(); !uoT8BBAk
oN[}i6^,e
O\ _ro.
} >|c?ZqW
} 2*<Zc|uNW
//负责部分文件的抓取 8h0CG]
**FileSplitterFetch.java z"T+J?V/
*/ sfipAM
package NetFox; qFK.ULgP`
4pl\qf
5'NNwc\
import java.io.*; 1)^\R(l
import java.net.*; =.7tS'
EcL6lNTR+
.8Bu%Sf
public class FileSplitterFetch extends Thread { 9tU"+
Pjk2tf0j`
]E-3/r$_cO
String sURL; //File URL 1I`F?MT
long nStartPos; //File Snippet Start Position _?:jZ1wZ
long nEndPos; //File Snippet End Position Arg/ge.y
int nThreadID; //Thread's ID 5q*s_acQ
boolean bDownOver = false; //Downing is over Ea&NJ]& g
boolean bStop = false; //Stop identical {f\wIZ-K A
FileAccessI fileAccessI = null; //File Access interface `kuu}YUi
aPzn4}~/_
YHO}z}f[!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Zj!,3{jX^
{ p@kRo#~l
this.sURL = sURL; $cIaLq
this.nStartPos = nStart; |,@D<
this.nEndPos = nEnd; G"` }"T0}
nThreadID = id; faDS!E' +
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \HbZ~I-
} &:5*^1oP
%-yzU/`JF
{j9TzR
public void run() pJvPEKN
{ iphC\*F
while(nStartPos < nEndPos && !bStop) 4/|x^Ky>G
{ i_Hm?Bi!F
x;)I%c
=TDKU
try{ >({qgzV`
URL url = new URL(sURL); ,\J 8(,%L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >U,&V%y
httpConnection.setRequestProperty("User-Agent","NetFox"); ,IyQmN y
String sProperty = "bytes="+nStartPos+"-"; =X?fA,
httpConnection.setRequestProperty("RANGE",sProperty); lwq:0Rj@Q
Utility.log(sProperty); 72d|Jbd
beBG40
JyZuj>` 6
InputStream input = httpConnection.getInputStream(); )][U6e
//logResponseHead(httpConnection); g5@JA^\vZT
9tJ0O5
.*x:
byte[] b = new byte[1024]; /Ne#{*z)hO
int nRead; {/]2~!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I8?
{ ySr,HXz
nStartPos += fileAccessI.write(b,0,nRead); B^/MwD>%
//if(nThreadID == 1) wHbkF#[:i
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;.uYWP|9
} 3A!a7]fW
^AH[]sE_
e&;e<6l&{
Utility.log("Thread " + nThreadID + " is over!"); iT :3e%
bDownOver = true; 9$\s v5
//nPos = fileAccessI.write (b,0,nRead); 6?F88;L
} DLrV{8%W
catch(Exception e){e.printStackTrace ();} QcL@3QC
} ?YW~7zG
} bI &<L O
t`z"=S
M YF ^zheD
//打印回应的头信息 GK}52,NM
public void logResponseHead(HttpURLConnection con) FB[b]+t`D{
{ \Ip)Lm0
for(int i=1;;i++) vW=-RTRH
{ p-}X=O$
String header=con.getHeaderFieldKey(i); :EV.nD7
if(header!=null) H7X-\K 1w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $Aw@xC^!
Utility.log(header+" : "+con.getHeaderField(header)); .2fvRN92
else G1z*e.+y
break; &YXJ{<s
} 309 pl
} s$Y>nH~T
T#Z&*
}*6BaB
public void splitterStop() 49MEGl;K0\
{ -'$ob~*
bStop = true; 45c?0tj
} )$n%4 :
TN0KS]^A3
cX-M9Cz
} +X/a+y-
g0grfGo2p
]W5*R07
/* EH|+S
**FileAccess.java oN1D&*
*//文件访问(定位，写) V.*TOU{{xh
package NetFox; FW|& iS$
import java.io.*; 1tNL)x"w
3NpB1lgh&:
%4*c/ c6
public class FileAccessI implements Serializable{ U>PZ3
LlX)xJ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?),b902C
RandomAccessFile oSavedFile; ^j\LB23
long nPos; H3rA ?F#+*
e"04jd/
[Fr](&Tx
public FileAccessI() throws IOException &42]#B"*
{ i|^Q{3?o#
this("",0); u<S`"MR:J
} [{7#IZL
uos8Mav{E
>G5aFk
public FileAccessI(String sName,long nPos) throws IOException 7H3v[ f^Q
{ y74Q(
oSavedFile = new RandomAccessFile(sName,"rw"); Ixxs(
this.nPos = nPos; ?J:w,,4m
oSavedFile.seek(nPos); ,R{&x7
} Wu][A\3D1
H a!,9{T
*$eH3nn6g
public synchronized int write(byte[] b,int nStart,int nLen) ='m$O
{ {W,5]-
int n = -1; -$Fj-pO\
try{ <&E}db
oSavedFile.write(b,nStart,nLen); (e7!p=D
n = nLen; ;73S;IPR
} (K[{X0T
catch(IOException e) J>_mDcPo
{ W22S/s
e.printStackTrace (); %%NoXW
} 9+1{a.JO
X?_rD'3
"|3I|#s
return n; ZG=]b%
} ]K(a32VCH
s 4`-mIa
i<ES/U\
} J||g(+H>
|#yu
2y!n c%
/* zVE" 6
**SiteInfoBean.java 3WwS+6R
*/ M1Q&)am
package NetFox; oKn$g[,SJh
e4YfJd
d4b! r
public class SiteInfoBean { s-CAo~,
8>C4w 5kF
/4r2B.91O
private String sSiteURL; //Site's URL Mk*4J]PP
private String sFilePath; //Saved File's Path 1GN^uia7
private String sFileName; //Saved File's Name 7UBDd1
private int nSplitter; //Count of Splited Downloading File H1-DK+Q:
)q<VZ|V
WDw<kX6p
public SiteInfoBean() Gpu[<Z4
{//nSplitter的缺省值为5 0ca0-vY
//default value of nSplitter is 5 g(&cq
this("","","",5); #eJfwc1JY
} T, #-: }
6/;YS[jX
I{$suPk
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +`F(wk["m
{ sPK]:iC
sSiteURL= sURL; f,O10`4s
sFilePath = sPath; f,ro1Nke
sFileName = sName; !>Nlp,r&~
this.nSplitter = nSpiltter; KF7w{A){
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l4RqQ+[KA;
} -)-:rRx-
$PMr)U
0Px Hf*
public String getSSiteURL() e,OXngC
{ 8g=O0Gb
return sSiteURL; >.SO2w
} ](oeMl18R
$l,U)
u/W{JPlL
public void setSSiteURL(String value) Y's=31G@
{ "*zDb|v
sSiteURL = value; 3JD62wtx
} *l d)nH{
*c#DB{N
pRfKlTU\
public String getSFilePath() }'<Z&NW6
{ 3~`\FuHHe
return sFilePath; zDYJe_m ~
} E`N`
Q8HNST($?
A#$l;M.3R
public void setSFilePath(String value) +!@xH];
{ x6>WvFZ
sFilePath = value; oxFd@WV5
} (l][_6Q
0uKm)t/
tln}jpCw
public String getSFileName() 8k{XUn
{ #p"F$@N
return sFileName; 5@.8O VPz
} {{A=^rr%C
V,ZRX}O
}!g$k $y
public void setSFileName(String value) '1!%yKc0
{ i_Lu
sFileName = value; U;&s=M0[
} qUe2(/TQu
tklS=R^Vn
v'L"sgW6I
public int getNSplitter() QdZHIgh`i
{ t":^:i'M
return nSplitter; ]mBlXE:Z
} TbMlYf]It
un6W|{4]
]$K58C
public void setNSplitter(int nCount) x=JZ"|TE
{ g7%vI8Y)@
nSplitter = nCount; 9Lt3^MKa"
} #SLiv
} =w7k@[Bq
Wi)N/^;n
5k_%%><: q
/* N*w{NB7L
**Utility.java Z_<Wr7D
*/ :)_P7k`>e/
package NetFox; eF8um$t9
^YPw'cZZ&
0/+TQD!L
public class Utility { iaJN~m\ M
Se/]J<]
.dBW{|gN
public Utility() 5tbi};
{ h7\EN
#|xj*+)H
o AS 'Z|
} tIX|oWC$q
p t{/|P
//线程睡眠 h1_KZ[X
public static void sleep(int nSecond) G_p13{"IM
{ @n=FSn6c
try{ doe u`
Thread.sleep(nSecond); vw q Y;7
} Vzrp9&loY
catch(Exception e) - zEQ/6
{ "6'# L,
e.printStackTrace (); o2(*5*b!@e
} $ "^yoL
} l< |)LDq~
u-Ip*1/wp
//日志 7+p=4i^@Zs
public static void log(String sMsg) m>?{flO
{ s2+s1%^Ll
System.err.println(sMsg); ;lb@o,R :
} Q[F$6m%o
HQ8;d9cGir
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public static void log(int sMsg) au1(.(
{ bxg9T(Bj
System.err.println(sMsg); Pd<>E*>}c.
} VJ(#FA2
} H]W59-{a
X6@G)68
$'VFb=?XrK
/* M>g\Y
**TestMethod.java {*PB+WGe
*/ >H?{=H+/#
package NetFox; DbkKmv&
6jtnH'E/
Ey;uaqt
public class TestMethod { :>g*!hpb
O9W|&LAL
i~6qOlLD-
public TestMethod() RI_3X5.KQ
{ ///xx/weblogic60b2_win.exe 'e>0*hF[
try{ #4*~ 4/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $/Q*@4t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7.l[tKh
SiteFileFetch fileFetch = new SiteFileFetch(bean); g k[8'
fileFetch.start(); 4`7:gfrO,
} h~ =UFE%'
catch(Exception e){e.printStackTrace ();} ]MP6VT
@ zE>n
x;Jy-hMNl
} /_P5UE(
!7lS=D(?
>h7qI-
public static void main(String[] args) 2 -uL
{ Z;QbqMj
new TestMethod(); i7f/r.
} V4PD]5ZW
} Xo>P?^c4?
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