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)); ]gG&X3jaKq
} (H-}z`sy/@
for(int i=0;i<nEndPos.length-1;i++) :zLeS-
{ W:* {7qJ
nEndPos = nStartPos[i+1]; 66%4p%#b4
} wTkcR^
nEndPos[nEndPos.length-1] = nFileLength; HA0Rv#p
} *zTEK:+_
} qjI.Sr70
{axMS yp;
yy#4DYht
//启动子线程 %m?$"<q_K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }Z3+z@L
for(int i=0;i<nStartPos.length;i++) *#g[ jl4
{ Z@ZSn0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \:|"qk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @w{"6xc%a
nStartPos,nEndPos,i); o0\d`0-el
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2V)qnMxAZJ
fileSplitterFetch.start(); j2%?-(U
} i*2l4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (4oO8aBB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #xBh62yIuP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D|Raj\R
nEndPos = " + nFileLength); QDpzIjJj
// fileSplitterFetch[nPos.length-1].start(); q"|#KT^)
X;%*+xQ^
V/W{d[86G
//等待子线程结束 )R@M~d-o
//int count = 0; *Ph@XkhU
//是否结束while循环 [[gfR'79{
boolean breakWhile = false; x3]y*6
+L\bg|;
!j-JMa?
while(!bStop) Egr'IbB
{ )W.Y{\D0
write_nPos(); 32Jl|@8,g
Utility.sleep(500); S1G3xY$0
breakWhile = true; 1./iF>*A
0V5{:mzA
S1D;Xv@
for(int i=0;i<nStartPos.length;i++) 'e5,%"5(c
{ Z|IFT1K
if(!fileSplitterFetch.bDownOver) o]O
{ sm96Ye{O{
breakWhile = false; jhkNi`E7
break; jO6yZt
} \\i$zRi
} UgAG2
if(breakWhile) vQhi2J'
break; ruK,Z,3Q
fgEMn;
;/|3U7{c
//count++; >C"QV`+
//if(count>4) /{HK0fd
// siteStop(); >J>|+W
} V07? sc<
B#Z-kFn@
'Bb@K[=s
System.err.println("文件下载结束！"); /woC{J)4p
} <N}*|z7=b
catch(Exception e){e.printStackTrace ();} to"[r
} a-Ef$(i_
$mZpX:7/u8
CY i{WV(:
//获得文件长度 bf&k:.v'8
public long getFileSize() Cv;\cI"&
{ ga+Z6|t
int nFileLength = -1; [$P.ek<
try{ \jGvom.
URL url = new URL(siteInfoBean.getSSiteURL()); tF=Y3W+L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h(H b+7g
httpConnection.setRequestProperty("User-Agent","NetFox"); +KKx\m*
K}1eQS&$a
Sw^-@w=!U5
int responseCode=httpConnection.getResponseCode(); 9&p;2/H
if(responseCode>=400) *&sXC@^@^
{ T_1p1Sg
processErrorCode(responseCode); gg}^@h&?
return -2; //-2 represent access is error {_<,5)c
} }$T!qMst{
?~#{3b
'p:L"L}Q?
String sHeader; aq<QKnU
P|{Et=R`1
[tY+P7j9)
for(int i=1;;i++) GYM6 `
{ [5O`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k>;a5'S
//Utility.log(in.readLine()); z3>oUq{
sHeader=httpConnection.getHeaderFieldKey(i); /'g"Ys?3
if(sHeader!=null) y.m;4((
{ UOtrq=y
if(sHeader.equals("Content-Length")) {%Ujp9i
{ I'%(f@u~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q1(6U6L
break; Vuu_Sd
} 5xF R7%_&
} 6*r3T:u3
else `.8#q^
break; 2lm{:tS
} *N|s+
} Gaxa~?ek
catch(IOException e){e.printStackTrace ();} a{%]X(';
catch(Exception e){e.printStackTrace ();} Y^P'slY{%
Up|>)WFw"
| *J-9
Utility.log(nFileLength); ;UB$Uqs6
}4M4D/=
j*05!j<'
return nFileLength; 8NS1*\z
} v'zj<|2
`GD>3-
WCPl}7>
//保存下载信息（文件指针位置） aA/.EAc7
private void write_nPos() byUz
{ m&X6a C'[
try{ oI6o$C
output = new DataOutputStream(new FileOutputStream(tmpFile)); gQ=g,X4
output.writeInt(nStartPos.length); FTfejk!
for(int i=0;i<nStartPos.length;i++) U%,N"]`
{ o)hQ]d
// output.writeLong(nPos); 2AZ)|dM'`
output.writeLong(fileSplitterFetch.nStartPos); G,J~Ed
output.writeLong(fileSplitterFetch.nEndPos); zrJ/Fs+s
} u/2!v(
output.close(); s*0PJ\E2
} t%f6P
catch(IOException e){e.printStackTrace ();} wWNHZv&
catch(Exception e){e.printStackTrace ();} U'tfsf/V
} 0 w#[?.
30Z RKrW"~
&R "Q
//读取保存的下载信息（文件指针位置） A+Xk=k5<
private void read_nPos() #=hI}%n
{ $SmmrM
try{ =1}Umn|ZLS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7>`VZ?
int nCount = input.readInt(); g, %xGQ4+
nStartPos = new long[nCount]; HX3R@^vo
nEndPos = new long[nCount]; Ka"Z,\T
for(int i=0;i<nStartPos.length;i++) o?$B<Cb"
{ &4ScwK:
nStartPos = input.readLong(); QQwD)WG
nEndPos = input.readLong(); WhR j@y
} 0H-~-z8Y
input.close(); ~e!b81
} 02~+$R]L
catch(IOException e){e.printStackTrace ();} d* 6 lJT
catch(Exception e){e.printStackTrace ();} lbtVQW0V;o
} krC4O2Fkj
@!:~gQ
l`vb
private void processErrorCode(int nErrorCode) De(\<H#
{ Hi 1@
System.err.println("Error Code : " + nErrorCode); domaD"C
} -K_p? l
&l=%*`On
M=hH:[6 &
//停止文件下载 >7VOytc
public void siteStop() y2U^7VrO
{ wf<=rW'
bStop = true; v{}i`|~J
for(int i=0;i<nStartPos.length;i++) aJC,
fileSplitterFetch.splitterStop(); L]goHs
%\ i 7
gqje]Zc<
} aF9p%HPDw
} DUk&`BSJ
//负责部分文件的抓取 4X@ <PX5
**FileSplitterFetch.java `!.)"BI/s
*/ DB'd9<
package NetFox; "Z&-:1tP{9
#S/]=D
0Jh^((i*
import java.io.*; 1XAXokxj
import java.net.*; :D>afC8,
(hB&OP5Fne
9U_uw Rv2
public class FileSplitterFetch extends Thread { 2Qqk?;^1
}hralef #N
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String sURL; //File URL (RR:{4I
long nStartPos; //File Snippet Start Position Awo H d7M
long nEndPos; //File Snippet End Position Zr0bVe+h
int nThreadID; //Thread's ID B>3joe}
boolean bDownOver = false; //Downing is over |&+0Tg~ZE
boolean bStop = false; //Stop identical Fq6sl}b(On
FileAccessI fileAccessI = null; //File Access interface y\DR,$Py
9 wun$!>&
=kz(1Pb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException El;\#la
{ BULf@8~(
this.sURL = sURL; (cX;a/BR
this.nStartPos = nStart; k !S0-/h
this.nEndPos = nEnd; <n4T*
nThreadID = id; 2nW:|*:/p6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =l_B58wrx
} )uvs%hK
_;G. QwHr
#,0PLU3%
public void run() YRXXutm
{ +/tNd2
while(nStartPos < nEndPos && !bStop) @)A)cBv#
{ 42a.@JbLQ
j@xerY
]Q Y:t:-
try{ !o+Y"* /
URL url = new URL(sURL); g\CRx^s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~C1lbn b
httpConnection.setRequestProperty("User-Agent","NetFox"); i`3h\ku
String sProperty = "bytes="+nStartPos+"-"; [Bn C_^[W
httpConnection.setRequestProperty("RANGE",sProperty); UQ;ymTqdc
Utility.log(sProperty); ,m| :U
V _(L/6
9qUc{ydt
InputStream input = httpConnection.getInputStream(); |H`}w2U[j
//logResponseHead(httpConnection); "|?zQ?E
OOzk@j^
v=kQ/h
byte[] b = new byte[1024]; -}u=tiNG
int nRead; :.863_/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L|hdV\
{ H ?Vo#/
nStartPos += fileAccessI.write(b,0,nRead); sN`2"t/s
//if(nThreadID == 1) ke'aSD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e6E{l
} v~f_~v5J!
#k%$A}9
s}8(__|
Utility.log("Thread " + nThreadID + " is over!"); /5qeNjI+2
bDownOver = true; !~+"TI}_%w
//nPos = fileAccessI.write (b,0,nRead); 'R&Y pR
} Aofk<O!M
catch(Exception e){e.printStackTrace ();} ftS^|%p
} @>Y.s6a
} : +Na8\d
DQC=f8
G:$Ta6=
//打印回应的头信息 Lnin;0~{
public void logResponseHead(HttpURLConnection con) T r|B:)X
{ ~HWH2g
for(int i=1;;i++) Y>Oh]?
{ nQe^Bn
String header=con.getHeaderFieldKey(i); ~#z8Q{!O
if(header!=null) b@GL*Z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Af~>}-`a
Utility.log(header+" : "+con.getHeaderField(header)); ObK-<kGcB
else ]mDsd*1
break; {+`'ZU6C
} v2OK/W,0
} V}?*kx~T2C
+m|S7yr'
^|u7+b'|t
public void splitterStop() 8+HXGqcv
{ HPz9Er
bStop = true; Z>0a?=1[
} &J>XKO nl
lD`@{A
5)tDgm
} >3{#S:
q1rBSlzN
DRp h?V\
/* ~ IPel
**FileAccess.java iLQFce7d|&
*//文件访问(定位，写) L#t^:%
package NetFox; (u/-ud1p
import java.io.*; <c`+ fPW
1~J:hjKQ
R,]J~TfPK
public class FileAccessI implements Serializable{ x;Qs_"t];3
I},]Y~Y3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R^v-%mG9
RandomAccessFile oSavedFile; uu5AW=j
long nPos; MR=dQc
gLm ]*
9%{V?r]k
public FileAccessI() throws IOException %y7&~me
{ .A(QqL>
this("",0); Ptt
} (d9G`
54X=58Q
'?j[hhfB-
public FileAccessI(String sName,long nPos) throws IOException ;kW+
{ F0.Rv):
oSavedFile = new RandomAccessFile(sName,"rw"); WruSL|4iH
this.nPos = nPos; 8C,}nh
oSavedFile.seek(nPos); .|$:%"O&X
} Fe r&X
=1kE2u
Hnq$d6F
public synchronized int write(byte[] b,int nStart,int nLen) A_8UPGh8
{ P\jnht
int n = -1; z%FBHj
try{ Z<P?P`
oSavedFile.write(b,nStart,nLen); |M8FMH[_
n = nLen; ;u:A:Y4V
} ~J~@mE2ks
catch(IOException e) xE$>;30b_
{ L=7Y~aL=
e.printStackTrace (); y cT@D/
} nj90`O.K
Z.^DJ9E<1
";kwh8wB
return n; g6AEMer
} PZ#\O
+#;t.&\80N
Z=[qaJ{]
} r$8(Q'
V4["+Y
n]3Lqe;
/* g-C)y 06
**SiteInfoBean.java M]5)u=}S-
*/ ;hf{B7
package NetFox; !7rk>YrY
#F|q->2`o
zl]Ic' _i
public class SiteInfoBean { (WCczXm)
-`f 1l8LD2
n_ 3g
private String sSiteURL; //Site's URL =<BPoGs5
private String sFilePath; //Saved File's Path S9 p*rk~
private String sFileName; //Saved File's Name ' ?4\
private int nSplitter; //Count of Splited Downloading File dmB _`R
KUV(vAY,
pW7#&@AR
public SiteInfoBean() 5bj9S
{//nSplitter的缺省值为5 Zra P\?
//default value of nSplitter is 5 pu"m(9
this("","","",5); U} K]W>Z
} M?gc&2Y
G7qB
pdw;SIoC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ii.?| u
{ PHxU6UPqy
sSiteURL= sURL; FQlYCb
sFilePath = sPath; -$2B!#]3
sFileName = sName; e{Y8m Xu
this.nSplitter = nSpiltter; Jan~Rran
hZwbYvu
4[XiD* *
} Fkvf[!Ci
ZRy'lW
>)j`Q1Qc\
public String getSSiteURL() rOo|.4w
{ s7Z+--I)L
return sSiteURL; _{C =d3
} n40&4n
P\rA>ZY
F97HFt6{
public void setSSiteURL(String value) )c<X.4
{ 3oQ?VP
sSiteURL = value; NMvNw?]
} d#U~>wr
UhX)?'J
Zk+c9,q
public String getSFilePath() `9`T,uJe
{ _'}Mg7,V
return sFilePath; q; ?Kmk
} />X"'G
2:jWO_V@
6JB*brO
public void setSFilePath(String value) E4cPCQyeH
{ lzbAx
sFilePath = value; lJJ`aYDp
} !+)5?o
v.!e1ke8D*
Q/%]%d
public String getSFileName() x4N*P
{ =JGL~t?
return sFileName; @c-| Sl
} 0F-%C>&g
EEp~\^-
PNB E
public void setSFileName(String value) gWGh:.*T
{ W @]t
sFileName = value; K[^BRn
} h|{DIG3
Vpe\Okt:
'E)g )@^
public int getNSplitter() :>*0./hG
{ 08qM?{zo^
return nSplitter; ]j+J^g
} ,382O$C
le150;7
^JY,K
public void setNSplitter(int nCount) pmuT7*<19
{ DmiZ"A
nSplitter = nCount; =`OnFdI
} Ca}V5O
} l_i&8*=Px
J,D^fVIw
QIC? `hk1
/* fA"9eUu
**Utility.java %hVI*p3
*/ ~[Z,:=z
package NetFox; mO0}Go8
.YlhK=d4
X<<FS%:+
public class Utility { $g!iy'4n*
{:TOm0eK
7srq~;j3
public Utility() gXvE^fE
{ HXb_k1n
k9!euj&
1'!%$D
} sP@7%p>wt
(2(y9r*1
//线程睡眠 %fIYWu`X
public static void sleep(int nSecond) ` 1vDp.
{ BV)) #D9
try{ vEc<|t
Thread.sleep(nSecond); c+ukVn`r
} Y(;u)uN_
catch(Exception e) E[Bj+mX9
{ $Ned1@%[
e.printStackTrace (); c@x6<S%*
} }q=tg9
} $QnsP#ePN
6 2LLfD
//日志 UgTgva>?
public static void log(String sMsg) 9dwLkr
{ .s%dP.P:i1
System.err.println(sMsg); i$6o>V6
} 8<=]4-X@
IqCh4y3
]2rCn};
public static void log(int sMsg) 6T6UIq
{ 8|~M!<
System.err.println(sMsg); d Z}|G-:
} nk"nSXm3SR
} 'kHa_
Q#lFt,.y
"%ZAL\x
/* MogIQ
**TestMethod.java KtcuGI/A
*/ 3oM&#a
package NetFox; b!T-{Ns6
&*; Z(ul&9
nq:'jdY5|
public class TestMethod { A2''v3-h8
59H~qE1Md
&F.L*M
public TestMethod() oA+'9/UY
{ ///xx/weblogic60b2_win.exe ut^6UdJ+`
try{ scPvuHzl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); a)' P/P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kd OIL2T
SiteFileFetch fileFetch = new SiteFileFetch(bean); N>IkK*v
fileFetch.start(); BeFXC5-qat
} _xGC0f (
catch(Exception e){e.printStackTrace ();} +J3Y}A4W3X
]RxWypA`
T/?C_i
} 3il/{bgM
B:6VD /qC
0,wmEV!)
public static void main(String[] args) XnB-1{a1
{ %FJB9?9=|
new TestMethod(); I+rLKGZC
} fv:&?gc
} h]WW?.
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