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)); CRKuN
} w!8xZu
for(int i=0;i<nEndPos.length-1;i++) FK~FC:K
{ S="teH[
nEndPos = nStartPos[i+1]; Vy6A]U\%
} *RpBKm&^7
nEndPos[nEndPos.length-1] = nFileLength; /xseI)y.B
} tn@MOOPl
} ^qgOgu
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vsDR@Y}k
//启动子线程 h0v4!`PQ-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; XC NM
for(int i=0;i<nStartPos.length;i++) aOWfu^&H:
{ ImnN&[Cu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <ic%c/mN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {y0`p1
nStartPos,nEndPos,i); s1/:Ts[3i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %8N=4vTJ
fileSplitterFetch.start(); _Vj uQ
} |}YeQl
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2wKW17wj,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b7nER]R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &Fxw19[G
nEndPos = " + nFileLength); E,fG<X{
// fileSplitterFetch[nPos.length-1].start(); iR`c/
e.<y-b?
d 6$,N|
//等待子线程结束 4Z"JC9As
//int count = 0; XNm%O
//是否结束while循环 V< ]l=JOd
boolean breakWhile = false; M1sR+e$"
p~h)@
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while(!bStop) Pn;Tg7oz
{ R,'` A.Kk
write_nPos(); GNIZHyT(O
Utility.sleep(500); _#2AdhCu
breakWhile = true; Q,1TD2)h
9N?BWv}
DQ a0S7I
for(int i=0;i<nStartPos.length;i++) a1p}y2
{ {8YNmxF#
if(!fileSplitterFetch.bDownOver) <l,Kg 'v
{ @}Y,A~
breakWhile = false; <+%#xi/_
break; pjI< cQ&
} Fo0dz
} /6$8djw
if(breakWhile) ^/k`URQ
break; v o9Fj
q_sQC5:s
pO~lVM
//count++; HS% P
//if(count>4) k8~/lE.Wy
// siteStop(); [kjmEMF9i
} SW^/\cJ^
.@(+.G
@\_l%/z{
System.err.println("文件下载结束！"); :mpR}.^hv
} .^Z^L F
catch(Exception e){e.printStackTrace ();} !x, ;&
} v;r!rZX
Tn'_{@E;
Lh"!Z
//获得文件长度 G31??L:<
public long getFileSize() :())%Xu3
{ ~qk5Mk4$
int nFileLength = -1; 0d%p<c
try{ T==(Pw7R7
URL url = new URL(siteInfoBean.getSSiteURL()); 5,pKv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :Ur=}@Dj
httpConnection.setRequestProperty("User-Agent","NetFox"); ]nEZQ+F
?\eq!bu
v@8=u4
int responseCode=httpConnection.getResponseCode(); n<. T6
if(responseCode>=400) quvdm68
{ hkh b8zS
processErrorCode(responseCode); JMnk~8O
return -2; //-2 represent access is error %Q0J$eC
} Bx>)i8P7i0
yLo{^4a.
##6_kcL:6G
String sHeader; R-8/BTls7
2I2#o9(Ar
`?X=@
for(int i=1;;i++) \;b)qB
{ 6"d^4L?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]Gm$0uS
//Utility.log(in.readLine()); ~sI$xX!
sHeader=httpConnection.getHeaderFieldKey(i); {u1Rc/Lw
if(sHeader!=null) 6__#n`
{ QzzV+YG$(4
if(sHeader.equals("Content-Length")) GCf3'u
{ t:|+U:! >
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o9l =Q
break; b`4R`mo
} ~}c`r4
} 2(, `9
else E%f;Z7G
break; | Q Y_ci
} }WN0L?h.E
} 3E!#?N|v
catch(IOException e){e.printStackTrace ();} XYKWOrkQqa
catch(Exception e){e.printStackTrace ();} X>n\@rTo
B"-gK20vY
:uAW
Utility.log(nFileLength); k{fCU%
z)Y<@2V*C
&IQp&
return nFileLength; $uA?c& e
} N@M(Iw
sGf\!w
iaqhP7!
//保存下载信息（文件指针位置） \LFRu
private void write_nPos() q/o|uAq
{ T:$zNX<f
try{ *3yeMxa
output = new DataOutputStream(new FileOutputStream(tmpFile)); Yfk){1
output.writeInt(nStartPos.length); 5$r`e+Nf'
for(int i=0;i<nStartPos.length;i++) kKFSCl/g
{ b6IYo!3
// output.writeLong(nPos); ]7QRelMiz+
output.writeLong(fileSplitterFetch.nStartPos); !bnuCc
output.writeLong(fileSplitterFetch.nEndPos); idm!6]
} )\:cL GM
output.close(); =:+k
} z2m%L0
catch(IOException e){e.printStackTrace ();} %SRUHx[D
catch(Exception e){e.printStackTrace ();} 1PMBo=SUe8
} d9zI A6y
$J/Z~(=JT
O7#ECUH
//读取保存的下载信息（文件指针位置） ~~?4w.k
private void read_nPos() Q0K4_iN)&
{ 00') Ol&
try{ wW3fsXu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `"0#lZ`n
int nCount = input.readInt(); C+r<DC3
nStartPos = new long[nCount]; Y",Fs(
nEndPos = new long[nCount]; z$3 3NM
for(int i=0;i<nStartPos.length;i++) Kilq Jg1%C
{ Lm kv.XF
nStartPos = input.readLong(); RVFQ!0 C
nEndPos = input.readLong(); `laaT5G\y
} <a-I-~
input.close(); or_x0Q
} 1cE3uA7
catch(IOException e){e.printStackTrace ();} x1m J&D
catch(Exception e){e.printStackTrace ();} }]pq&v!
} "_qH+=_R
wVvk{tS
pV:c`1\`
private void processErrorCode(int nErrorCode) d}K"dr:W5
{ 7qB}Hvh
System.err.println("Error Code : " + nErrorCode); }5H3DavW
} 6#xP[hlR[
7xP>AU)y
s(Of EzsH=
//停止文件下载 3K2`1+kBVG
public void siteStop() #zC_;u$
{ K/Q^8%Z
bStop = true; J4qFU^
for(int i=0;i<nStartPos.length;i++) \(t.|
fileSplitterFetch.splitterStop(); .+<Ul]e/
T}(J`{9i
.6%-Il
} =,0E]MZ
} QN_Zd@K*A
//负责部分文件的抓取 Zx(VwB2
**FileSplitterFetch.java 1F*gPhm
*/ }&d@6m]
package NetFox; xrX^";}j
)v1n#m,W
ylF%6!V}4V
import java.io.*; ':8yp|A|
import java.net.*; >Vr+\c
zbdmz
#C1u~db
public class FileSplitterFetch extends Thread { B./Lp_QK
'AN3{
VLW<"7I 6\
String sURL; //File URL 0c4H2RW
long nStartPos; //File Snippet Start Position i]8HzKuiW
long nEndPos; //File Snippet End Position Rh-e C6P
int nThreadID; //Thread's ID !/G2vF"
boolean bDownOver = false; //Downing is over TI-8I)
boolean bStop = false; //Stop identical @Otom'O
FileAccessI fileAccessI = null; //File Access interface 1hj']#vBu
zhH-lMNj-
1u&}Lq(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException w66iLQ\@
{ @b\/\\{
this.sURL = sURL; YaJ[39V
this.nStartPos = nStart; K!6k<
this.nEndPos = nEnd; G(F}o]
nThreadID = id; q/,>UtRr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 53d8AJ_@X
} Qvh: hkR
y^:!]-+
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public void run() bX%9'O[-
{ 7A|n*'[T>
while(nStartPos < nEndPos && !bStop) PSz|I8 c
{ fOEw]B#@
T+7O+X#
:R+}[|FV
try{ Uk=jQfA*J
URL url = new URL(sURL); b: UTq 7^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [(U:1&x&
httpConnection.setRequestProperty("User-Agent","NetFox"); X>^St&B}fC
String sProperty = "bytes="+nStartPos+"-"; X4LU/f<f
httpConnection.setRequestProperty("RANGE",sProperty); iJE $3
Utility.log(sProperty); VdpwZ
(K"U#Zn
Z-W>WR
InputStream input = httpConnection.getInputStream(); MG<kvx~2
//logResponseHead(httpConnection); bcFG$},k
e[f}Lxln
Y.&nxT95=
byte[] b = new byte[1024]; aMQfg51W:
int nRead; t<5$85Y~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) hnag<=
{ LIYj__4=|
nStartPos += fileAccessI.write(b,0,nRead); r9<OB`)3+
//if(nThreadID == 1) rf_(pp)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fB+4mEG@
} $8gj}0}eH
x5_V5A/@LU
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Utility.log("Thread " + nThreadID + " is over!"); 7 sv 3=/`
bDownOver = true; lB9 9J"A
//nPos = fileAccessI.write (b,0,nRead); sJ[I<
} U:xY~>
catch(Exception e){e.printStackTrace ();} +jQHf-l
} c3,YA,skb!
} 4SRX@/ #8*
R&Y+x;({
._j9^Ll
//打印回应的头信息 k@MAi*
public void logResponseHead(HttpURLConnection con) %fB]N
{ `6a
for(int i=1;;i++) b_2bg>|;
{ gE$D#PZa
String header=con.getHeaderFieldKey(i); xi|T7,\X
if(header!=null) fz'@ON
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %O]]La
Utility.log(header+" : "+con.getHeaderField(header)); 53efF bo
else #!="b8F
break; ]t$wK
} ]E/^(T-O
} Dy`;]-b6u
/ i[F
C;]}Ht:~I
public void splitterStop() lezX-5Z
{ 7]se!k,
bStop = true; r'!L}^n
} h=tzG KI
Z4 y9d?g%b
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} SVKjhZK
bzYj`t?
%0 cFs'
/* l*eJa38
**FileAccess.java 3%gn:.9N
*//文件访问(定位，写) DJ)Q,l*|N9
package NetFox; MvV\?Lzj
import java.io.*; _Q XC5i
FI|jsO 3
PM]|S`
public class FileAccessI implements Serializable{ WbF[4x
6! `^}4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #Bu W
RandomAccessFile oSavedFile; h=:Ls]ZU
long nPos; .d mUh-
o@T-kAEf-.
b]A9$-
public FileAccessI() throws IOException WBc,/lgZ
{ a}(xZ\n^D;
this("",0); cV8Bl="gqe
} O^/z7,
%DOV)Qc2
3vdhoS|
public FileAccessI(String sName,long nPos) throws IOException u*n%cXY;J/
{ ;5S'?fj
oSavedFile = new RandomAccessFile(sName,"rw"); Q8d-yJs&
this.nPos = nPos; '0ks`a4q
oSavedFile.seek(nPos); hbfN1"z
} #Y|t,x;
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+UvT;"
public synchronized int write(byte[] b,int nStart,int nLen) /:S&1'=
{ 3` ,u^ w
int n = -1; p;nRxi7'
try{ o'Rr2,lVi
oSavedFile.write(b,nStart,nLen); {N.JA=
n = nLen; \3K%>
} ^:hI bF4G
catch(IOException e) NgI n\) =0
{ Xg<R+o
e.printStackTrace (); 7bk=D~/nSg
} .|?UqZ(,
W"3YA+qpI
u7>{#]
return n; QVT|6znw
} #E`wqI\'
r2b_$
o57r ,`N
} pDYcsC{p
rf\/Y"D
Kg8n3pLAX
/* d@b" ~r}
**SiteInfoBean.java CpGy'Ia
*/ X}fu $2
package NetFox; %p; 'l
`J l/@bE=
"A9qC*6[
public class SiteInfoBean { Pl/}`H:R&
q0sdL86
;rj|>
private String sSiteURL; //Site's URL W]B75
private String sFilePath; //Saved File's Path =PM6:3aKh
private String sFileName; //Saved File's Name [\BLb8
private int nSplitter; //Count of Splited Downloading File B!j7vXM2
MP6Py@J45
;N(9nX}%)
public SiteInfoBean() 7gnrLc$]O
{//nSplitter的缺省值为5 U*Sjb% Qb
//default value of nSplitter is 5 r)]8zK4;=
this("","","",5); HI\V29 a
} jA'7@/F/
lnQfpa8j
l$:?82{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^.gBHZ
{ UlD]!5NO
sSiteURL= sURL; R!z32 <5k
sFilePath = sPath; `fM]3]x>
sFileName = sName; ehTRw8"R
this.nSplitter = nSpiltter; O[<YYL0
O'.sK pXe
%=*nJvYS
} is6M{K3
JqTR4[`Z\
Oj]4jRew
public String getSSiteURL() 'UFPQ
{ .~AQxsGH
return sSiteURL; Y'U]!c9
} E'^$~h$
9D`p2cO
q]\GBRp
public void setSSiteURL(String value) Nc_Qd4<[@G
{ v/G)E_
sSiteURL = value; BenUyv1d
} o |"iW" +
2t}^8
P.Gmj;
public String getSFilePath() g;-6Hg'
{ w:3CWF4q]
return sFilePath; phP%
} =IEei{
XGcl9FaO}
'z$!9ufY,
public void setSFilePath(String value) Aa!#=V1d
{ .T*89cEu
sFilePath = value; <(tnClAn
} @g%^H)T
u;Rm/.
ZOzwO6(_
public String getSFileName() / 0ra]}[(
{ 4NDT5sL
return sFileName; }!^`%\ %\
} t2_pwd*B
B!AJ*
8;<3Tyjzu
public void setSFileName(String value) bFB.hkTP
{ g$T% C?
sFileName = value; HLb`'TC3r+
} |_u|Td(n
\H{UJ
$Ma*qEB
public int getNSplitter() z;lWr(-x
{ _)a!g-Do7
return nSplitter; /#Lm)-%G
} Sej(jJX1
8T"8C
&'"dYZj{
public void setNSplitter(int nCount) $TY1'#1U;
{ uZXG"
nSplitter = nCount; \}:;kO4f
} I*EHZctH
} |'!9mvt=
M d.^r5r
cNG`-+U'
/* /|WBk}
**Utility.java ,T0q.!d
*/ [WUd9fUL
package NetFox; |wkUnn4UB8
\xjI=P'-25
_r?.%]\.
public class Utility { m~RMe9Qi
9/dI 6P7
|*y'H*
public Utility() O`TM}
{ UI_u:a9Q/
`2a7y]?
.mvpFdn
} k~=W1R%
V]6CHE:BS
//线程睡眠 HImQ.y!B
public static void sleep(int nSecond) fDrjR6xV
{ k*|WI$
try{ xF8 8'p'
Thread.sleep(nSecond); Ry`Y +
} b>'y[P!
catch(Exception e) UUR` m
{ +qee8QH
e.printStackTrace (); 5K {{o''
} {(_>A\zi
} AI9#\$aGV
@%gth@8
//日志 k[8{N
public static void log(String sMsg) C7_nA:Rc
{ |`Q2K9'4bL
System.err.println(sMsg); dH~i
} ~pPj
Y~P* !g
"#=WD
public static void log(int sMsg) IaYaIEL-
{ fT0+inRG
System.err.println(sMsg); cjc1iciZ
} >{.|Ng4K
} Fh~ pB>t
AR6hfdDDT
J9q[u[QZ9O
/* n7iIY4gZ
**TestMethod.java { v#wU
*/ Xo ,U$zE
package NetFox; {LqahO*
?h3t"9
U IHe^?R
public class TestMethod { 9N;y^ Y\
0<u(!iL
2W6t0MgZ
public TestMethod() iE* Y@E5x0
{ ///xx/weblogic60b2_win.exe m?`?T
try{ bI+ TFOP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 68nBc~iAm
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q=#@g
SiteFileFetch fileFetch = new SiteFileFetch(bean); *9|*21
fileFetch.start(); :\IZ-
} FGu#Pa
catch(Exception e){e.printStackTrace ();} s E0ldN"
xAu&O\V
Zz^!QlF
} MBO>.M$B
xMD]b
^ SW!S_&Z2
public static void main(String[] args) +a74] H"
{ *s (L!+
new TestMethod(); DUWSY?^c
} ;]Ko7M(4
} ;\rKkH"K8n
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