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)); l_Ffbs_6t
} qBkI9H
for(int i=0;i<nEndPos.length-1;i++) tmCm54
{ ~|7jz;$V
nEndPos = nStartPos[i+1]; 99<0xN(25
} m)]A$*`<
nEndPos[nEndPos.length-1] = nFileLength; ~BSE8M+r
} w=r3QKm#K
} )kq3q5*_
b)5z'zQu
DKcg
//启动子线程 pX nY=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #DL( %=:
for(int i=0;i<nStartPos.length;i++) oZY2K3J)
{ 0^27grU>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ot]Y/;K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2I2#o9(Ar
nStartPos,nEndPos,i); w# t[sI"IT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \;b)qB
fileSplitterFetch.start(); 6"d^4L?
} H|uvcvf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -RSPYQjz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <NLor55.]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $SP*hkU
nEndPos = " + nFileLength); jf_0IE
// fileSplitterFetch[nPos.length-1].start(); e2SU)Tr%b
|+^-b}0
fCA/
//等待子线程结束 m}x&]">9
//int count = 0; |CC(`<\R
//是否结束while循环 e@-"B9~
boolean breakWhile = false; ~BNLzt3%O
?Q~6\xA
Pmj]"7Vd[
while(!bStop) BZXP%{njS
{ #b~wIOR)Z
write_nPos(); Llf |fayq
Utility.sleep(500); (ei;Y~i
breakWhile = true; Ew4>+o!
31w9$H N
NW.<v /?=,
for(int i=0;i<nStartPos.length;i++) cR0RJ$[d
{ S_z}h
if(!fileSplitterFetch.bDownOver) UeG$lMV
{ SX{shM2
breakWhile = false; yMQuM:d
break; H?dmNwkPY
} PgKA>50a
} 6~ *w~U
if(breakWhile) Wp0e?bK_
break; Z=ayVsJ3
q<YteuZJ,
4{:W5eT!/
//count++; _.xT :b36
//if(count>4) YHVJg?H3
// siteStop(); O};U3=^0f
} T;eA<,H
Su<Ggv"
+TzF*Np
System.err.println("文件下载结束！"); |P_\l,f8`
} xZ51iD$
catch(Exception e){e.printStackTrace ();} [e2sUO0~r
} ;CU<\
*0 ;DCUv
x*H4o{o0
//获得文件长度 \haJe~
public long getFileSize() $c-h'o
{ dbkkx1{>Y
int nFileLength = -1; TzXivE@mm
try{ [<)/ c>Y
URL url = new URL(siteInfoBean.getSSiteURL()); )`RF2Y-A7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gr'M6&>
httpConnection.setRequestProperty("User-Agent","NetFox"); Dt~Jx\\
gI&& LwT4
&%~2Wm
int responseCode=httpConnection.getResponseCode(); {iP^51fy
if(responseCode>=400) Lm kv.XF
{ RVFQ!0 C
processErrorCode(responseCode); })V9d
return -2; //-2 represent access is error ^A8'YTl
} Ni5~Buf
la ~T)U7
U!:Q|':=h
String sHeader; ?_e2)+q8YG
Y[AL!h
Hno:"k?
for(int i=1;;i++) :X>%6Xj?RV
{ Zho d%n3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); JM5w`=
//Utility.log(in.readLine()); h1.]Nl C
sHeader=httpConnection.getHeaderFieldKey(i); |x|#n
if(sHeader!=null) 0`=#1u8
{ '`q&UPg]
if(sHeader.equals("Content-Length")) L\||#w
{ P8K{K:T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J4qFU^
break; \(t.|
} .+<Ul]e/
} T}(J`{9i
else .6%-Il
break; =,0E]MZ
} QN_Zd@K*A
} Zx(VwB2
catch(IOException e){e.printStackTrace ();} 1F*gPhm
catch(Exception e){e.printStackTrace ();} }&d@6m]
xrX^";}j
)v1n#m,W
Utility.log(nFileLength); nDnSVrvd-i
':8yp|A|
>Vr+\c
return nFileLength; zbdmz
} #C1u~db
B./Lp_QK
'AN3{
//保存下载信息（文件指针位置） VLW<"7I 6\
private void write_nPos() 6[kp#
{ i]8HzKuiW
try{ Rh-e C6P
output = new DataOutputStream(new FileOutputStream(tmpFile)); !/G2vF"
output.writeInt(nStartPos.length); TI-8I)
for(int i=0;i<nStartPos.length;i++) @Otom'O
{ oD]tHuDa
// output.writeLong(nPos); cq`v8
output.writeLong(fileSplitterFetch.nStartPos); B&&:A4
output.writeLong(fileSplitterFetch.nEndPos); ^PIUA'
} _}.BZ[i
output.close(); MtC\kTW
} V6Kw71'9
catch(IOException e){e.printStackTrace ();} oLEqy
catch(Exception e){e.printStackTrace ();} m72r6Yq2@
} K_ P08
T]\_[e:'
1BK-uv:
//读取保存的下载信息（文件指针位置） 12;"=9e!
private void read_nPos() ec/1Z8}p
{ !6:kJL}U
try{ DjK:)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lz.ta!6
int nCount = input.readInt(); MXsSF|-
nStartPos = new long[nCount]; N;ed_!
nEndPos = new long[nCount]; tW;1
for(int i=0;i<nStartPos.length;i++) 5LU8QHj3
{ ; F% 3b47
nStartPos = input.readLong(); nZe2bai
nEndPos = input.readLong(); /k3v\Jq{
} F$P8"q+
input.close(); ]6NpHDip1
} iE$qq~%
catch(IOException e){e.printStackTrace ();} m.ev~Vv~
catch(Exception e){e.printStackTrace ();} 6m_ fEkS[
} ].=&^0cg
s86Ij>VLf
9|v3lGK(
private void processErrorCode(int nErrorCode) \<WRk4D
{ =n>&Bl-Bl
System.err.println("Error Code : " + nErrorCode); ~;nh|v/e
} 45e-A{G~
n}(/>?/
(055>D6
//停止文件下载 <&:OSd:%
public void siteStop() v0)I rO
{ b6sj/V8
bStop = true; >ENZ['F
for(int i=0;i<nStartPos.length;i++) {/SUfXq
fileSplitterFetch.splitterStop(); Mz,G;x}
@&(0]kZ6
F]kn4zr
} z97RNT|Y7U
} `R@1Sc<*|
//负责部分文件的抓取 %fB]N
**FileSplitterFetch.java ^$-ID6
*/ `6a
package NetFox; b_2bg>|;
H&`0I$8m
W8{g<. /
import java.io.*; z\wY3pIr2
import java.net.*; EM9K^l`
wp7<0PP
[@YeQ{
public class FileSplitterFetch extends Thread { Q!7il<S
A)"?GK{*
KwO;ICdJ
String sURL; //File URL jd]Om r!
long nStartPos; //File Snippet Start Position w1tWyKq
long nEndPos; //File Snippet End Position 6U|An*
int nThreadID; //Thread's ID T%|{Qo<j
boolean bDownOver = false; //Downing is over IiW*'0H:/
boolean bStop = false; //Stop identical ~n9x ,
FileAccessI fileAccessI = null; //File Access interface Aw#@}TGT
c'#w 8V
}ZaZPB/_}P
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /BEE.`6yI5
{ -JgN$Sf
this.sURL = sURL; [XK^3pT_
this.nStartPos = nStart; XdS&s}J[I
this.nEndPos = nEnd; {/|RKV83
nThreadID = id; x_Y03__/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +/+:D9j ,
} VZhtx)
6! `^}4
Eod'Esye5
public void run() })~M}d2LXB
{ r"HQ>Wn
while(nStartPos < nEndPos && !bStop) hO8~Rg
{ ->"Z1
yhTC?sf<
_,r2g8qm
try{ +%E)]*Ym
URL url = new URL(sURL); \N3A2L)l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >+}yI}W;e
httpConnection.setRequestProperty("User-Agent","NetFox"); n:dnBwY
String sProperty = "bytes="+nStartPos+"-"; wz[Xay9jW
httpConnection.setRequestProperty("RANGE",sProperty); 3` ,u^ w
Utility.log(sProperty); s>pM+PoGYd
^HiI
y}aKL(AaU
InputStream input = httpConnection.getInputStream(); /i:c!l9
//logResponseHead(httpConnection); a ][t#`
\tCxz(vKz
/[V}
byte[] b = new byte[1024]; I(rZ(|^A
int nRead; u9c^:Op
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zDK"Y{
{ GpwoS1#)0|
nStartPos += fileAccessI.write(b,0,nRead); /Py1Q
//if(nThreadID == 1) /7[U J'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >~+qU&'2
} $X\deJ1Hi
*WzvPl$e
@O]v.<8
Utility.log("Thread " + nThreadID + " is over!"); "+dByaY
bDownOver = true; -K%hug
//nPos = fileAccessI.write (b,0,nRead); 1iLrKA
} e-E0Bp
catch(Exception e){e.printStackTrace ();} ~7;AV(\%e
} [N=v=J9
} 8?l/x
yq6Gyoi<
TmEJ!)*
//打印回应的头信息 DH IC:6EY
public void logResponseHead(HttpURLConnection con) G*N}X3H:o
{ ==!k99`f,
for(int i=1;;i++) h85kQ^%
{ ov$S
String header=con.getHeaderFieldKey(i); wk9qyv<
if(header!=null) UI]UxEJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?GT,Y5
Utility.log(header+" : "+con.getHeaderField(header)); b fj]Q
else Kry^47"
break; L9}%tEP
} IIh \d.o
} Fo.p}j+>
'nQQqx%v
lnQfpa8j
public void splitterStop() l$:?82{
{ Rlwewxmr
bStop = true; G2 {R5F !
} >{1 i8 b@
OAiSE`
v$d^>+Y#
} `z1E]{A
!+o`,KTYp
96#aGh>
/* jCK 0+,;
**FileAccess.java VKb=)v[K
*//文件访问(定位，写) bdYx81
package NetFox; yM PZ}
import java.io.*; s2kom)
:ceT8-PBRx
>c30kpGg
public class FileAccessI implements Serializable{ =yCz!vc
ir<K"wi(2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L (@".{T
RandomAccessFile oSavedFile; EC8Fapy
long nPos; @Wl2E.)K;
=N^j:t
U UYx-x
public FileAccessI() throws IOException _t-e.2a v
{ N2.(0 G
this("",0); spG3"Eodi
} MZWicfUy
c`s ]ciC
(yO8G-Z0
public FileAccessI(String sName,long nPos) throws IOException 'z$!9ufY,
{ LUKt!I0l
oSavedFile = new RandomAccessFile(sName,"rw"); L43]0k
this.nPos = nPos; q]rqFP0C
oSavedFile.seek(nPos); e13' dCG
} 78h!D[6
WT'?L{
j`l'Mg
public synchronized int write(byte[] b,int nStart,int nLen) <tI_u ~P
{ 2q}lSa7r
int n = -1; !.cno&
try{ &]S\GnqlU]
oSavedFile.write(b,nStart,nLen); j<PpCL_8%
n = nLen; +@BjQ|UZ
} :TRhk.
catch(IOException e) zW:r7 P.
{ \H{UJ
e.printStackTrace (); $Ma*qEB
} z;lWr(-x
_)a!g-Do7
cL+bMM$4r~
return n; C+vk9:"
} /;;$9O9
Y*-dUJK-`
,tl(\4n
} M-zqD8D
P.W@5:sD
V2o1~R~
/* 58[.]f~0
**SiteInfoBean.java zOn%\
*/ d 6=Z=4w
package NetFox; E6+ 6
I#U)
7R#$Hm
public class SiteInfoBean { 2B[I- K s
'tJ@+(tqw
vC%Hc/&.}
private String sSiteURL; //Site's URL "7}e~*bM?`
private String sFilePath; //Saved File's Path get$r5
private String sFileName; //Saved File's Name )~C+nb '6/
private int nSplitter; //Count of Splited Downloading File It8s#oq8
qt=nN-AC(
b0aV?A}th
public SiteInfoBean() EncJB
{//nSplitter的缺省值为5 [?S-on.
//default value of nSplitter is 5 i'MpS
this("","","",5); +?ilTU
} >vZ^D
KA{JSi
u iR[V~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zw}Wm4OH
{ a]t| /Mq
sSiteURL= sURL; wvPS0]
sFilePath = sPath; ^-g-]?q
sFileName = sName; LDYk\[81
this.nSplitter = nSpiltter; IP+.L]S
`s~[q
H{+[ ,l
} ;hCUy=m.
?vg|;Q
gh<2i\})'
public String getSSiteURL() jPmp=qg"q
{ 0/fA>%&
return sSiteURL; 3)_(t.$D
} @ Br?
c+.?+g
Dz<vIMLF{
public void setSSiteURL(String value) Q)93+1]
{ W3]?>sLE*
sSiteURL = value; JqP~2,T
} W+ v#m>G
{ v#wU
Xo ,U$zE
public String getSFilePath() {LqahO*
{ ?h3t"9
return sFilePath; 9e0t
} 63T4''bwu
3u&)6C?YM
UsnIx54D3
public void setSFilePath(String value) ]<:qMLg
{ _g%h:G&^
sFilePath = value; hZUnNQ
} 6a4-VX5
@0fiui_
Fg^Z g\X3
public String getSFileName() KpfQ=~'
{ "q3W&@
return sFileName; 3GM9ZPeN:
} Km!~zG7<
NzG] nsw
*s6(1S
public void setSFileName(String value) rk< 3QXv
{ p$}1V2h;
sFileName = value; C>Cb
} %d2\4{{S
3$h yV{
3R`eddenF
public int getNSplitter() y/OPN<=*
{ }= (|3\v
return nSplitter; \>)#cEX5
} cp L'
]Aa.=
'I5~<"E
public void setNSplitter(int nCount) baz~luM
{ /tu\q
nSplitter = nCount; {]3Rk
} ~s-"u *>
} IpKpj"eoLy
JXk<t5@D
;Ff5ooL{
/* nPj &a
**Utility.java &0JCZ/e
*/ nx|b9W<
package NetFox; "XWO#,Ue
zz1]6B*eX
1D2Yued
public class Utility { u8Oo@xf0Fr
9t_N9@
zi= gOm
public Utility() 3#~w#Q0%
{ +JPHQx'W
f~v@;/HL
nW!pOTJq21
} &ngG_y8}&
M}qrF~
//线程睡眠 d D;r35h=
public static void sleep(int nSecond) Qcs>BOV~
{ *S] K@g
try{ N)o/}@]6
Thread.sleep(nSecond); qZ rv2dT
} .Uh|V-
catch(Exception e) /rZ`e'}
{ Uq:CM6q\
e.printStackTrace (); (cdtUE8
} taqmtXU=(
} Jpr`E&%I6
"t:9jU
//日志 }TsND6Ws3
public static void log(String sMsg) aT20FEZ;
{ z P=3B%$
System.err.println(sMsg); zjUT:#(k
} %fB!XCW
9P\R?~3
q.Vcb!*$
public static void log(int sMsg) Q4QF_um
{ YLFM3IaP
System.err.println(sMsg); [FN4_
} ;ep@ )Y
} Bxs0m]
6}^6+@LG
uH=^ILN.
/* ;SVAar4r
**TestMethod.java !1fAW!8
*/ }8)iFP&"
package NetFox; Y0ouLUlI
*|^}=ioj*
2/.I6IbL
public class TestMethod { drW}w+!
$x|4cW2
;.#l[
public TestMethod() ^UiSezcI
{ ///xx/weblogic60b2_win.exe oV=~Q#v
try{ C ehz]C
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); OYayTKxN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iK=SK3)vR
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;vLg4k
fileFetch.start(); jgd^{!
} 2kV{|`1
catch(Exception e){e.printStackTrace ();} ,n\'dMNii
>gGdzL
L6IF0`M<,I
} D<UX^hU
O[v(kH'
;@lC08SE
public static void main(String[] args) Gz@/:dW^vZ
{ IPEJ7n49
new TestMethod(); O\ph!?L
} Hsvu&>[`S
} VVVw\|JB>
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