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)); O-lh\9{'R
} ^21f^>k(
for(int i=0;i<nEndPos.length-1;i++) yqb<<4I
{ 2d;xAX]
nEndPos = nStartPos[i+1]; "X(=
} !@Vp Bl
nEndPos[nEndPos.length-1] = nFileLength; -zLI!F 0
} ZFuJ2 :
} @$yYljP
cTaD{!zm5
?| LB:8
//启动子线程 hGo|2@sc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f uNXY-;
for(int i=0;i<nStartPos.length;i++) EbYH?hPo
{ O#5( U.E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /N{@g.edL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <IDzv'
nStartPos,nEndPos,i); 0:+uw` %
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kBT}Siw
fileSplitterFetch.start(); ,Y8X"~{A
} k\<Ln w
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N b[o6AX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~rX6owBq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %e<dV\x?T
nEndPos = " + nFileLength); jL%}y1m?
// fileSplitterFetch[nPos.length-1].start(); ~d `4W<1a
N&h!14]{Z
6Oba}`)q9
//等待子线程结束 8 (h
//int count = 0; ^QQNJ
//是否结束while循环 sK/"
boolean breakWhile = false; i6:yNb ='
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"EhO )lR
while(!bStop) }~'Wz*Gm
{ "}+/0$F
write_nPos(); y/6LMAI
Utility.sleep(500); |B$\3,
breakWhile = true; 4^ 6L])y
KmOa^vY1.T
xLK0~|_#!
for(int i=0;i<nStartPos.length;i++) P2JRsZ.
{ j4r,_lH^r
if(!fileSplitterFetch.bDownOver) B]F7t4Y!
{ "I FGW4FnL
breakWhile = false; P}QbxkS 8
break; 9ufs6z
} AHD%6 \$
} hBE>ea
if(breakWhile) pDq_nx9
break; TPFmSDq
"$pgmf2
U?j>28
//count++; K.1yncS^
//if(count>4) slfVQ809
// siteStop(); *Y0,d`
} nnl9I4-O
NB+O;
2vQ^519
System.err.println("文件下载结束！"); kK|+W,
} !*UdY(
catch(Exception e){e.printStackTrace ();} )_K@?rWS
} !QS<;)N@
'\\Cpc_g
J}\]<aC
//获得文件长度 4F6o
public long getFileSize() _N';`wjDY
{ xG/qDc
int nFileLength = -1; t3g!5
try{ i4rF~'h@
URL url = new URL(siteInfoBean.getSSiteURL()); lB~'7r`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $i>VI
httpConnection.setRequestProperty("User-Agent","NetFox"); oa !P]r
{=7i}xY]T
1^^D :tt
int responseCode=httpConnection.getResponseCode(); S Tk#hhx
if(responseCode>=400) >D62l*VC)
{ 1tz .e\
processErrorCode(responseCode); f.^w/ GJO/
return -2; //-2 represent access is error ScoHtX3
} tgA |Vwwk
Pp hQa!F$
S9oGf
String sHeader; ]X|G+[Ujv
S`w)b'B!M
!PIdw~YC
for(int i=1;;i++) S]/+n>
{ D07u?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *S_Iza #&x
//Utility.log(in.readLine()); Pv.@Y30
sHeader=httpConnection.getHeaderFieldKey(i); 5K~6`
if(sHeader!=null) <t37DnCgI
{ AB\4+ CLV
if(sHeader.equals("Content-Length")) n5>N9lc
{ TJ:Lz]l >
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {hR2NUm
break; |h/2'zd^-
} ,0~TvJS
} $7d"9s\$"
else $u"$mg7x
break; ??V["o T
} R,1,4XT
} ^0-=(JrC
catch(IOException e){e.printStackTrace ();} b.;}Hq>
catch(Exception e){e.printStackTrace ();} Tj9q(Vq
rtE,SN
h cXqg
Utility.log(nFileLength); IyP].g1"U
X&Lt?e,&
=T$- #bA)
return nFileLength; ]#n4A|&H
} 1_lL?S3,a@
w,9F riW
u`|fmVI
//保存下载信息（文件指针位置） \]%U?`A
private void write_nPos() Y&:i^k
{ 3: Uik
try{ ow[qpP[
output = new DataOutputStream(new FileOutputStream(tmpFile)); p]4 sN
output.writeInt(nStartPos.length); 3IFU{0a`
for(int i=0;i<nStartPos.length;i++) #mYxO
{ =YIQ _,{u
// output.writeLong(nPos); HXI}f\6x
output.writeLong(fileSplitterFetch.nStartPos); E:k?*l
output.writeLong(fileSplitterFetch.nEndPos); 6~>k]G
} (Lnh> '2
output.close(); cC.DBYV+-
} R0}%
catch(IOException e){e.printStackTrace ();} 1[^d8!U
catch(Exception e){e.printStackTrace ();} dZmq
} y>8?RX8
sN2l[Ous
*cIXae^Y7
//读取保存的下载信息（文件指针位置） +)SX
private void read_nPos() ? Q}{&J
{ VIzZmd
try{ EA.U>5Fq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &=bI3-
int nCount = input.readInt(); to7)gOX(
nStartPos = new long[nCount]; |=s3a5sl
nEndPos = new long[nCount]; 4>*`26
for(int i=0;i<nStartPos.length;i++) Vk-_H)*r
{ W:\VFPf2
nStartPos = input.readLong(); gzF&7trN
nEndPos = input.readLong(); +E4_^
} YSyW '~!b
input.close(); fZ$2bI=
} LKcrr;
catch(IOException e){e.printStackTrace ();} UhK,H
catch(Exception e){e.printStackTrace ();} GWKefH
} 3yN1cd"#?
r$5!KO
51x,[y+Xe
private void processErrorCode(int nErrorCode) x{$NstGB
{ c&&UT-Z
System.err.println("Error Code : " + nErrorCode); E<dN=#f6
} &&O=v]6,V
*Y Ox`z!R
WM26-nR
//停止文件下载 1~Nz6
public void siteStop() ~\P.gSiz
{ ^iNR(cwgX
bStop = true; Yo:&\a K[
for(int i=0;i<nStartPos.length;i++) l<0V0R(
fileSplitterFetch.splitterStop(); > R=YF*t
zdCt#=QV?R
-eTGRr
} dyd_dK/
} 7(H/|2;-d8
//负责部分文件的抓取 D$HxPfDZ
**FileSplitterFetch.java srL,9)OC
*/ xh0!H| R
package NetFox; uypD`%pC
AI2CfH#:C
V 6F,X`7
import java.io.*; }qTvUs
import java.net.*; $`%.Y&A
/l L*U
s/V[tEC*z
public class FileSplitterFetch extends Thread { 6F2}|c
rQJoaP+\q
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String sURL; //File URL R)/w
long nStartPos; //File Snippet Start Position +dfSCs
long nEndPos; //File Snippet End Position I$$!YMm.N
int nThreadID; //Thread's ID i+}M#Y-O
boolean bDownOver = false; //Downing is over V6Y!0,w!a
boolean bStop = false; //Stop identical bGZy0.
FileAccessI fileAccessI = null; //File Access interface h(BN6ZrzKd
aC*J=_9o#
n" sGI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `|R{^Sk1o
{ K\G|q}E/1
this.sURL = sURL; TUG3#PSnm*
this.nStartPos = nStart; =B 9U
this.nEndPos = nEnd; xQQ6D
nThreadID = id; o&=m]hKpQl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6o!"$IH4
} 8MIHp[vm%
Ne%X:h
T~la,>p|}
public void run() c}A^0,"z>
{ TO<g@u]*
while(nStartPos < nEndPos && !bStop) #ed]zI9O
{ Uu ,Re
j2+&B9(
)jg3`I@
try{ 3jeR;N]x
URL url = new URL(sURL); 5@Sb[za
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b~r ?#2K
httpConnection.setRequestProperty("User-Agent","NetFox"); ~jgd92`{z
String sProperty = "bytes="+nStartPos+"-"; V;$lgTs|'
httpConnection.setRequestProperty("RANGE",sProperty); IcB>Hg5
Utility.log(sProperty); \a<E3 <
AK[c!mzx
q_!3<.sf
InputStream input = httpConnection.getInputStream(); >a,w8^7
//logResponseHead(httpConnection); u!(|y9p
|$Td-M^)
QeGU]WU{
byte[] b = new byte[1024]; 1z)+P1nH]
int nRead; {zw#My
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gCmGFQE-f
{ V5=Injs*
nStartPos += fileAccessI.write(b,0,nRead); bbz86]AhY
//if(nThreadID == 1) OnG?@sW+4!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p?Y1^/
} 3'8~H]<W
7\.5G4dr%
|nD`0Rbw
Utility.log("Thread " + nThreadID + " is over!"); IySlu^a
bDownOver = true; =uHTpHR
//nPos = fileAccessI.write (b,0,nRead); Xr@0RFdr[
} x[]n\\a?
catch(Exception e){e.printStackTrace ();} M:ttzsd
} sviGS&J9h
} 9rhz#w
bp }~{]:b
(q)W<GYP
//打印回应的头信息 @ ~PL|Pp_
public void logResponseHead(HttpURLConnection con) xMe[/7)4
{ &4DWLI
for(int i=1;;i++) ~U`aH~R
{ 1_A< nt?'R
String header=con.getHeaderFieldKey(i); y<)x`&pcD
if(header!=null) f+rBIE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wEdXaOEB5
Utility.log(header+" : "+con.getHeaderField(header)); |KuH2,n0
else Zvc{o8^z
break; \hg12],#:@
} xk#/J]j
} kc}e},k
VP[ J#TPU
4]Krx m`8
public void splitterStop() C@xh$(y
{ 86[TBX5'
bStop = true; TtHqdKL
} o_?YYw-:
-q[?,h
7uYJ_R
} 3iDRt&y=.
h9No'!'!
O`*}N1No[
/* *edB3!!
**FileAccess.java ondF
*//文件访问(定位，写) m/<7FU8
package NetFox; Uc.K6%iI
import java.io.*; \ZXH(N*>2t
Q~nc:eWD
}=NjFK_6
public class FileAccessI implements Serializable{ 1%H]2@
8!1vsEqv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G"wy?
RandomAccessFile oSavedFile; 0Y{A
long nPos; [^#6.xH
IS!sJc
moh7:g
public FileAccessI() throws IOException k<m{Wp;-
{ ~h -0rE
this("",0); gE|_hfm(
} "Q^Ck7
'(;`t1V8k
rlgp1>89
public FileAccessI(String sName,long nPos) throws IOException -Zkl\A$>
{ G >bQlZG
oSavedFile = new RandomAccessFile(sName,"rw"); c{zQX0
this.nPos = nPos; >a[)F
oSavedFile.seek(nPos); +Ibcc8Qud
} L9"V$MO
5Osx__6$t
-|T.APxB
public synchronized int write(byte[] b,int nStart,int nLen) SO9j/
{ 2ACN5lyUS
int n = -1; L'.7V ~b{
try{ 525W; mu{
oSavedFile.write(b,nStart,nLen); Jc/*w
n = nLen; J&wrBVv1uk
} 0KE+RzrB
catch(IOException e) {U>B\D
{ Y$shn]~
e.printStackTrace (); V|)3l7IC<
} (i1]+.
,F]Y,"x:
jUYb8:B
return n; #2s$dI
} K08xiMjl
5$/ED3mcK
ng"R[/)In
} xM'bb5
b 'jZ4{+W
/{6PwlP5
/* |#>\GU=!
**SiteInfoBean.java u?i_N0H
*/ 8i;EpAwB
package NetFox; j@ lHgis
!K'j[cA^
h,"K+$
public class SiteInfoBean { zuwlVn
F|Pf-.r`t
akoK4!z
private String sSiteURL; //Site's URL [LbUlNq^B@
private String sFilePath; //Saved File's Path |wZcVct~
private String sFileName; //Saved File's Name Kf/1;:^
private int nSplitter; //Count of Splited Downloading File fYBmW')
KEEHb2q
>+ulLQqe
public SiteInfoBean() f%<kcM2
{//nSplitter的缺省值为5 Cz` !j
//default value of nSplitter is 5 p3`ND;KQ
this("","","",5); n=qN@u;Fi#
} h\k@7wgu
c 2t<WRG
@9Rgg9r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R7pdwKD
{ `fYICp
sSiteURL= sURL; WBvh<wTw;
sFilePath = sPath; yPs4S?<s
sFileName = sName; z|E/pm$^
this.nSplitter = nSpiltter; (e.?). e
&@NTedg!
d e)7_pCF|
} K Rs e
4>x]v!d
hH_&42E6
public String getSSiteURL() >$Sc}a3
{ |*W_
return sSiteURL; 2:3-mWE
} TrD2:N}dI
Er509zZ,[
1j"_@?H[
public void setSSiteURL(String value) &3~lZa;D
{ B)>r~v]
sSiteURL = value; cAnL,?_v
} Q$u&/g3NvL
mCah{~
n@>h"(@i
public String getSFilePath() WZ,}]D
{ .LMOmc=(
return sFilePath; B /q/6Pp
} IdTatE|^
{S[+hUl
-hL0}Wy$N
public void setSFilePath(String value) OI/m_xx@j
{ ~0/tU#&
sFilePath = value; =)QtE|p,77
} xgeDfpF'
%8C,9q
d^b(Uo=$
public String getSFileName() z 3((L
{ TNun)0p
return sFileName; +pMa-{
} Zfwhg4G~
vfBIQfH
v_=xN^R
public void setSFileName(String value) k_d)
{ f0"N
sFileName = value; LelCjC{`1
} b~$B0o)
$r>$ u
Qg9*mlm`
public int getNSplitter() 3%HF"$Gg
{ ,zXP,(x
return nSplitter; q-? k=RX`
} PH!^ww6
(S<Z@y+d
j<,Ho4v}_
public void setNSplitter(int nCount) ly_@dsU'
{ i*ibx;s-
nSplitter = nCount; Z:_ wE62'
} !W\Zq+^^J3
} dOG]Yjc
pX 4:WV
,EsPm'`?A/
/* 7 k:w3M
**Utility.java U-h'a: K
*/ |aWeo.;c
package NetFox; *aem5E`c
^lw0} i
3jeB\
public class Utility { Gz09#nFZk
KH=4A-e,0
hKx*V"7/#\
public Utility() _.}1 Y,Q
{ %5[,U)X"
*;N6S~_'Y
'>"riEk
} 'J[n}r
;7/ ;4Z
//线程睡眠 J~jxmh
public static void sleep(int nSecond) S2APqRg*
{ c>~q2_}W(
try{ C4,;l^?=%
Thread.sleep(nSecond); !\'NBq,
} KCDbE6
catch(Exception e) LA +BH_t&
{ 7A,QA5G]C
e.printStackTrace (); n8K FP
} S`w_q=-^8
} h=a-~= 8
9>QGsf.3
//日志 mQ$a^28=qR
public static void log(String sMsg) l^~E+F~
{ \jR('5DcB
System.err.println(sMsg); }Cs.Hm0P
} r}>q*yx:
Tr\6AN?o
3AQu\4+A
public static void log(int sMsg) a ](Jc)
{ 2bnF#-(
System.err.println(sMsg); .,vF%pQ
} M94zlW<
} 3QZ~t#,7ij
O>vbAIu
B8G9V6KS-
/* e6 &-f
**TestMethod.java sJ3O ]
*/ xPcH]Gs^b
package NetFox; J$+K't5BZ
U??T>
=!R+0
public class TestMethod { arQEi
!dcGBj
|0wHNRN_
public TestMethod() !kpnBgmU
{ ///xx/weblogic60b2_win.exe C@P4}X0,=
try{ H?H(=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); bP+b~!3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L_~vPp
SiteFileFetch fileFetch = new SiteFileFetch(bean); ' K\ $B_
fileFetch.start(); d*cAm$
} .[Hv/?L
catch(Exception e){e.printStackTrace ();} H)@f_pfj(
qX_( M2oLU
<H]1 6
} ,suC`)R
#P,C9OQD
+`(,1L1
public static void main(String[] args) $qp,7RW
{ _v\L'`bif
new TestMethod(); (\qO~)[0
} HLruZyN4
} 9)~Ha iVB
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