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)); c> 0R_
} 363KU@`
for(int i=0;i<nEndPos.length-1;i++) z50P* eS
{ ZA+w7S3
nEndPos = nStartPos[i+1]; ^).
} K1$
nEndPos[nEndPos.length-1] = nFileLength; F}~qTF;H
} Bwl@Muw
} '\M]$`Et
5=_bK^Am
hQ ?zc_3
//启动子线程 fSF_O}kLp
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; cDIZkni=
for(int i=0;i<nStartPos.length;i++) %#x l+^
{ bRD-[)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )uu(I5St
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ge7Uety
nStartPos,nEndPos,i); Nsn~mY%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H<9_BA?
fileSplitterFetch.start(); H~ E<ek'~
} %<0'xJ%%Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z`<5SHQd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); bH.SUd)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UZpQ%~/
nEndPos = " + nFileLength); 3<)+)n
// fileSplitterFetch[nPos.length-1].start(); Z 4QL&?U
/>n!2'!
`a `>Mtl
//等待子线程结束 \`;1[m
//int count = 0; ;,/4Ry22j-
//是否结束while循环 "H#pN;)+
boolean breakWhile = false; 5.$/]2VK
-}u1ZEND
" GY3sam
while(!bStop) xzHb+1+p
{ [/o BjiBA
write_nPos(); z HT#bP:o
Utility.sleep(500); #/> a`Ur_
breakWhile = true; Z!-V&H.
d$^@$E2f
y* :C~
for(int i=0;i<nStartPos.length;i++) V|G*9^Y
{ UD=[::##
if(!fileSplitterFetch.bDownOver) qP0UcG
{ D"gv:RojD
breakWhile = false; C8W_f( i~
break; OS-k_l L
} NvC @
} $zM \Jd
if(breakWhile) =~k}XB
break; #(QS5J&Qq
0t[ 1#!=k
pgQ^w0BQV
//count++; /dO*t4$@?
//if(count>4) @/,0()*dL
// siteStop(); .W\JvPTC
} +%H=+fJ2}
&NOCRabc
@?>5~
System.err.println("文件下载结束！"); eA*We
} z\"9T?zoo
catch(Exception e){e.printStackTrace ();} k t'[
} fZoQQ[s
:k-@w5(
PhAD:A
//获得文件长度 \l%##7DRp]
public long getFileSize() a6@k*9D>
{ |8tKN"QG
int nFileLength = -1; Po&'#TC1
try{ # [ +n(
URL url = new URL(siteInfoBean.getSSiteURL()); pedyWA>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T"t.t%(8
httpConnection.setRequestProperty("User-Agent","NetFox"); qI>,PX
yuC|_nL
&dPUd~&EL
int responseCode=httpConnection.getResponseCode(); Yxy!&hPLv:
if(responseCode>=400) -(7oFOtg
{ m%'T90mi
processErrorCode(responseCode); F"cZ$TL]
return -2; //-2 represent access is error 3xN_z?Rg
} gF`hlYD
Xvk+1:D
~^'WHuzPy
String sHeader; #l h' !
M N (o
6VS_L@
for(int i=1;;i++) LcT;7yv
{ F|cli <
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1/,~0N9
//Utility.log(in.readLine()); L)8%*X
sHeader=httpConnection.getHeaderFieldKey(i); 65nK1W`i
if(sHeader!=null) g6+5uvpd
{ E62_k 0q
if(sHeader.equals("Content-Length")) Ls+vWfF=#
{ Rn`DUYg
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9R">l5u
break; 8 &v)Vi-
} &O#1*y Z
} 7kITssVHI
else ~T/tk?:8Vi
break; P,b&F
} cltx(C>
} qA[cF$CIl)
catch(IOException e){e.printStackTrace ();} mN>(n+ly
catch(Exception e){e.printStackTrace ();} Q+/P>5O/
:sw@1
z`eMb
Utility.log(nFileLength); :Gzp (@<@e
f]mVM(XZN
?o`:V|<v
return nFileLength; R](cko=
} =Ot_P7'5gv
Gx4{ 9
4'tY1d
//保存下载信息（文件指针位置） ]omBq<ox'Y
private void write_nPos() HGDiwA
{ G*,7pc
try{ XL9-N?(@
output = new DataOutputStream(new FileOutputStream(tmpFile)); fQwLx
output.writeInt(nStartPos.length); t BG 9Mn
for(int i=0;i<nStartPos.length;i++) .;S1HOHz4
{ d^v.tYM$N
// output.writeLong(nPos); [>U2!4=$M
output.writeLong(fileSplitterFetch.nStartPos); p$ETAvD
output.writeLong(fileSplitterFetch.nEndPos); j/F('r~L
} 2kk; z0f
output.close(); A`Rs n\
} -%Ce
catch(IOException e){e.printStackTrace ();} =diGuIB
catch(Exception e){e.printStackTrace ();} |f\WVGH
} 4?+jvVq
~3&hvm[IQ
OT$++cj^
//读取保存的下载信息（文件指针位置） \KS.A 4
private void read_nPos() ^.
{ $pt~?ZZ3-
try{ mB6%. "
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Gd'_X D
int nCount = input.readInt(); Kr<UPr
nStartPos = new long[nCount]; us8HXvvp{
nEndPos = new long[nCount]; E$&bl
for(int i=0;i<nStartPos.length;i++) +WKN&@
{ r:Q=6j,
nStartPos = input.readLong(); 3.g4X?=zd
nEndPos = input.readLong(); V#+F*w?&D
} VS!v7-_N5
input.close(); yW\kmv.O
} _3NH"o d
catch(IOException e){e.printStackTrace ();} _ysakn
catch(Exception e){e.printStackTrace ();} !qHB?]
} `Q/\w1-Q
7Ka4?@bQ
ori[[~OyB
private void processErrorCode(int nErrorCode) FQE(qltf,
{ cct/mX2&~
System.err.println("Error Code : " + nErrorCode); P}>>$$b\Yi
} Ab:ah7!
,rF!o_7
G:wO1f6
//停止文件下载 B2KBJ4rI[1
public void siteStop() 1C]BaPbL
{ p:eaZ
bStop = true; #/8 Nav
for(int i=0;i<nStartPos.length;i++) `B:hXeI
fileSplitterFetch.splitterStop(); 1_]%,
TJ>1?W\Z
baL<|& c
} GXNkl?#
} Y^U^yh_!^
//负责部分文件的抓取 |5&7;;$
**FileSplitterFetch.java #yU"n-eLR
*/ %o0H#7'
package NetFox; la4%Vqwgu
c,M"a
( z F_<
import java.io.*; 0I do_V
import java.net.*; [-81s!#mkw
W^S]"N0u
VR A+p?7-
public class FileSplitterFetch extends Thread { )K`tnb.Pf
Pj_DI)^
q_L. Sy|)
String sURL; //File URL !R#PJH/TM
long nStartPos; //File Snippet Start Position QFoCi&
long nEndPos; //File Snippet End Position tA'5ufj*:
int nThreadID; //Thread's ID .I$+ E
boolean bDownOver = false; //Downing is over Q`4Ia<5B
boolean bStop = false; //Stop identical }W[=O:p
FileAccessI fileAccessI = null; //File Access interface a<>cbP
l<ZHS'-;8
2R^Eea
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s8qpK; O
{ Fpwhyls
this.sURL = sURL; Z!jJ93A"
this.nStartPos = nStart; Ke]'RfO\
this.nEndPos = nEnd; ,^<39ng
nThreadID = id; %K06owV(S)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +Jn\`4/J:
} >IA1 \?(
@+)T"5_Y[
Y?zo")
public void run() u6IM~kk>5
{ a40>_;}:x
while(nStartPos < nEndPos && !bStop) sJl>evw
{ Z:V<P,N
|z&7KoYK'
ER@RWV2
try{ :S!!J*0
URL url = new URL(sURL); HCe/!2Y/%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >Rb jdM5K4
httpConnection.setRequestProperty("User-Agent","NetFox"); UlKg2p
String sProperty = "bytes="+nStartPos+"-"; l|vT[X/g
httpConnection.setRequestProperty("RANGE",sProperty); SJi;_bVf
Utility.log(sProperty); 8]O#L}"
d>c`hQ(V
[a}Idi` K
InputStream input = httpConnection.getInputStream(); 8YgRJQZ!
//logResponseHead(httpConnection); 78<fbN5}r
oz[G'[\}F
=}u?1~V
byte[] b = new byte[1024]; i.eMrzJ|
int nRead; y&\t72C$Fi
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) sb1tQ=u[
{ npbf>n^R
nStartPos += fileAccessI.write(b,0,nRead); ~DB:/VSmu
//if(nThreadID == 1) J~ +p7S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fD8GAav
} k)y<iHR_o
A1z<2.R
Y$j!-l5z
Utility.log("Thread " + nThreadID + " is over!"); [ :Sl~
bDownOver = true; [D<(xr&N%
//nPos = fileAccessI.write (b,0,nRead); 8,VEuBZ
} =)N6R
catch(Exception e){e.printStackTrace ();} / T_v8{D
} O`N,aYo
} O#>,vf$
:!fY;c?
}*aj&
//打印回应的头信息 G Uh<AG*+
public void logResponseHead(HttpURLConnection con) V%C'@m(/SZ
{ ~3-+~y=o~
for(int i=1;;i++) ?[WUix;
{ -yu$Mm
String header=con.getHeaderFieldKey(i); s&wm^R
if(header!=null) 3Q)"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \8vZZt
Utility.log(header+" : "+con.getHeaderField(header)); M9(lxu y1
else "+ k}#<P4\
break; fi&>;0?7
} i1]}Q$
} 1-.i^Hal
7qWa>fX
/#L4ec-'
public void splitterStop() %rEP.T\i
{ 9VIAOky-
bStop = true; 2Qc_TgWF
} 3RcnoXX_
Z*v`kl
}>3jHWxLc
} at2)%V)
_.EM])b
pE0@m-p
/* E>2AG3)
**FileAccess.java e ]2GAJLI
*//文件访问(定位，写) Z7?\ >4V
package NetFox; %j{*`}
import java.io.*; rTJ;s
')2LP;(
89P7iSV#*
public class FileAccessI implements Serializable{ NpbZt;%t
fl4'dv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R4zOiBi'B
RandomAccessFile oSavedFile; Z]5xy_La
long nPos; `>lY$EBG@[
wNNg"}&P
77]lpmC
public FileAccessI() throws IOException tZ*>S]qD
{ 8k.#4}fP
this("",0); kn`O3cW/
} #&z'?x^a
)2u_[Jc=
R[m+s=+
public FileAccessI(String sName,long nPos) throws IOException 9PaV*S(\TR
{ %.fwNS
oSavedFile = new RandomAccessFile(sName,"rw"); 5*Dh#FRp
this.nPos = nPos; 5CH8;sMK
oSavedFile.seek(nPos); bZj5qjl`x
} y"K[#&,0
yD0DPtti
'c >^Aai
public synchronized int write(byte[] b,int nStart,int nLen) zqRps8=
{ o+- 0`!yj
int n = -1; |f$gQI!XW
try{ ]9wTAb
oSavedFile.write(b,nStart,nLen); ogV v 8Xb
n = nLen; |F qujZz
} ?dk)2
catch(IOException e) ,WAJ& '^
{ [EQTrr( D
e.printStackTrace (); rV*Ri~Vx
} `?d` #)Ck
s>{\^T7y
zOy_qozk
return n; "K;""]#wg0
} )L_@l5l
/U6ry'
j|[>f
} vJX0c\e
e YiqTWn:
Ypinbej
/* { / ,?3
**SiteInfoBean.java )t2eg1a:
*/ c;n\HYk
package NetFox; Lg-!,Y
2cZgG^
ajf(Ii\/
public class SiteInfoBean { Pv*]AF;9pQ
Oz<#s{Z
"DX2Mu=
private String sSiteURL; //Site's URL /38XaKc{6
private String sFilePath; //Saved File's Path y3P4]sq
private String sFileName; //Saved File's Name P\@efq@!
private int nSplitter; //Count of Splited Downloading File jm'^>p,9G
-"x@V7X
\J-D@b;
public SiteInfoBean() <EY{goW
{//nSplitter的缺省值为5 AMK(-=
//default value of nSplitter is 5 D23 c/8K
this("","","",5); g?@fHFct
} wb39s^n
@z=L\e{
f$--y|=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hK %FpGYA
{ tNYuuC%N
sSiteURL= sURL; B!4~A{
sFilePath = sPath; 0E@*&Ru
sFileName = sName; NuXII-
this.nSplitter = nSpiltter; &&zsUAkS
,=: -&~?
#K/95!)
} ROO@EQ#`Z
E+$D$a
<2N=cH'
public String getSSiteURL() u$D%Iz
{ [7,q@>:CS
return sSiteURL; _auFt"n
} HzsQ`M4cA
gIKQip<
3MDs?qx>s
public void setSSiteURL(String value) HI[Pf%${
{ &#!1 Y[e^
sSiteURL = value; a/[)A _-
} C>QWV[F
'k[vcnSz\/
,G[Y< ~Hy
public String getSFilePath() a&7uRR26
{ s|k&@jH)
return sFilePath; }:!X@C~
} 3KtJT&RuL
oFsV0 {x%)
wVc^l
public void setSFilePath(String value) y<c7RK]
{ 3`Xzp
sFilePath = value; dq0!.gBT2
} !.499H3
!1Ht{cA0
wEQZ9?\
public String getSFileName() HumL(S'm
{ 7"OJ,Mx%
return sFileName; xl@~K^c]
} bL5u;iy)
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{vQ:4O!:
public void setSFileName(String value) BKYyc6iE
{ fm!\**Q1
sFileName = value; |OuIQhoE
} _ER. AKY
`^|l+TJG
JoD@e[(
public int getNSplitter() [$#G|>x
{ Of}C.N8
return nSplitter; RrdLh z2N
} OP\L
1\g r ;b
`O`MW} c
public void setNSplitter(int nCount) )jh~jU?c@
{ AS'+p%(
nSplitter = nCount; 8isQL
} =q*c}8R_0
} yet~
yD@1H(yM
lbC,*U^
/* Vlge*4q
**Utility.java Z*=$n_ G
*/ X8wtdd]64
package NetFox; KN>h*eze
_hMFmI=r[
}y vH)q
public class Utility { I+31:#d
7m}fVLk
}'K-1:
public Utility() ,sT5TS q
{ Y~?Z'uR
Pz0TAb
"=V!-+*@G@
} U2v;GIo$yU
A2$05a$%
//线程睡眠 <j3|Mh_(I
public static void sleep(int nSecond) k=&n>P
{ }7_$[r'_oI
try{ E()%IC/R
Thread.sleep(nSecond); 0 ZSn r+
} U*,\UF
catch(Exception e) d]MpE9@'v
{ OL_jU2,fv
e.printStackTrace (); e3?z^AUXm
} wuM'M<J@
} u4bVp+
qh6rMqq
//日志 }0iHf'~DH*
public static void log(String sMsg) Sh?eb
{ qW'L}x
System.err.println(sMsg); J~50#vHY
} y|zIuI-p
>]o>iOz;]
Z]x6np
public static void log(int sMsg) !~V^GlY
{ h4+*ssnYV
System.err.println(sMsg); d24_,o\_
} ;--D?Gs]Qr
} >(.Y%$9"E
7|GSs=
qw>vu7/z
/* "h|kf% W
**TestMethod.java \A)Pcc}7
*/ A;dD'Kgl
package NetFox; ZX#60o8
|o'r?"
n{&;@mgI
public class TestMethod { w'E?L`c
2e03m62*
p#_5w
public TestMethod() GLX{EG9Z
{ ///xx/weblogic60b2_win.exe EVC]B}
try{ M|zTs\1I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CGkx_E]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _pDfPLlY&
SiteFileFetch fileFetch = new SiteFileFetch(bean); U3`?Z`i(
fileFetch.start(); Eggu-i(rD
} Pn6~66a6
catch(Exception e){e.printStackTrace ();} %(W8WLz}
L u'<4 R
B*w]yL(
} ),[@NK&=
`xx3JQv[
&]shBvzl^
public static void main(String[] args) Y=g]\%-PB
{ h=JW^\?\]
new TestMethod(); >5?:iaq z
} zqBzataR:
} \ 9iiS(e
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