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)); T.I'c6|
} O@@nGSc@
for(int i=0;i<nEndPos.length-1;i++) #$S~QS.g
{ 4_VgJ9@
nEndPos = nStartPos[i+1]; 5&p}^hS5
} `=hCS0F
nEndPos[nEndPos.length-1] = nFileLength; !c)F;
} 9F3,
} $Q#n'#c
rucw{) _
>e/>@ J*
//启动子线程 T:kliM"z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;6hoG(3 +
for(int i=0;i<nStartPos.length;i++) In?+
{ v=G*K11@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wX2U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), o NA ]G]
nStartPos,nEndPos,i); $S<B\\ %
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :F"IOPfU5[
fileSplitterFetch.start(); ~{{S<S v
} P^F3,'N
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \e4AxLP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }U'9 d#N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9a=:e=q3#
nEndPos = " + nFileLength); 7WSP0Xyz
// fileSplitterFetch[nPos.length-1].start(); C=oeRc'r1W
AlDp+"|
+|g*<0T5<
//等待子线程结束 rQT%~oM:
//int count = 0; LYYz=oZOE!
//是否结束while循环 0U%tjYk(
boolean breakWhile = false; &8i$`6wY
`~d7l@6F
RYvdfj.ij
while(!bStop) DRRQ]eK0
{ 7{M&9| aK
write_nPos(); q M_c-^F
Utility.sleep(500); X(E`cH |
breakWhile = true; #]1jvB
|)>+& xk
u=L Dfn
for(int i=0;i<nStartPos.length;i++) Kh=\YN\E<
{ {06-h %qr
if(!fileSplitterFetch.bDownOver) L / PAC
{ c0e[vrP:
breakWhile = false; V0A>+
break; d<xi/
} ;k@]"&t
} ^bPpcm=
if(breakWhile) 2jhJXM=~
break; NGi)Lh|
qY%|Uo
|H5GWZ O{^
//count++; P4yUm(@
//if(count>4) Ms5qQ<0v_
// siteStop(); $s1/Rmw
} Q}\\0ajS)
Zbre5&aU
`'iO+/;GY
System.err.println("文件下载结束！"); ;lE=7[UJ3X
} r$4d4xtK
catch(Exception e){e.printStackTrace ();} E7R%G OH
} O{c#&/.K
Pw]+6
_oa*E2VN
//获得文件长度 -a|b.p
public long getFileSize() #w5%^HwO
{ *"_W1}^
int nFileLength = -1; ~kV>nx2
try{ iu<Tv,{8
URL url = new URL(siteInfoBean.getSSiteURL()); Jo[&y,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LrO[l0#'Q
httpConnection.setRequestProperty("User-Agent","NetFox"); 8q]"CFpa
+<@1)qZ(E
O\cc=7
int responseCode=httpConnection.getResponseCode(); `2+TN
if(responseCode>=400) 32 j){[PL3
{ 0 5?`W&:9
processErrorCode(responseCode); /YPG_,lRA
return -2; //-2 represent access is error D0bpD
} ]Q.S Is
Sru0j/|H\
*^{j!U37s
String sHeader; ,if~%'9j
F ]D^e{y
73!NoDxb
for(int i=1;;i++) CTg79 ITYk
{ l{3zlXk3z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n?6^j8i
//Utility.log(in.readLine()); -0;{
sHeader=httpConnection.getHeaderFieldKey(i); !Y|xu07
if(sHeader!=null) f:P;_/cJc
{ lz>.mXdx
if(sHeader.equals("Content-Length")) .1^Kk3
{ $_'<kH-eP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ncUhCp?'
break; ->{\7|^
} #%$@[4"V
} YVF@v-v-,
else $SA @ "
break; f$}g'r zl
} KMfIp:~
} 0wqw5KC
catch(IOException e){e.printStackTrace ();} rVOF
catch(Exception e){e.printStackTrace ();} daA&!vnbH*
,'YKL",
Kn1u1@&Xd
Utility.log(nFileLength); ZBU<L+#
kda*rl~c
u#u/uS"
return nFileLength; =7kn1G.(
} .&bc3cW
]o'dr r
G]xN#O;
//保存下载信息（文件指针位置） ,f?B((l
private void write_nPos() >#S}J LZ
{ 7|Wst)_~j
try{ ]3]B$
output = new DataOutputStream(new FileOutputStream(tmpFile)); D=D.s)ns*
output.writeInt(nStartPos.length); $@^\zg1n
for(int i=0;i<nStartPos.length;i++) w0yzC0yBk
{ Xe`$SNM
// output.writeLong(nPos); ^f(El(w
output.writeLong(fileSplitterFetch.nStartPos); 4R01QSbd
output.writeLong(fileSplitterFetch.nEndPos); ebL0cK?
} 75P!`9bE
output.close(); &,Rye Q
} 7?_gm>]a
catch(IOException e){e.printStackTrace ();} i 28TH Jh
catch(Exception e){e.printStackTrace ();} K",Xe>
} v'`qn
%,S:^Rvv
(IHR {m
//读取保存的下载信息（文件指针位置） 8&+u+@H
private void read_nPos() :*l\j"fX5
{ tmoclK-
try{ ?a,`{1m0\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?)Gb=
int nCount = input.readInt(); Om7 '_}
nStartPos = new long[nCount]; E\Iz:ES^
nEndPos = new long[nCount]; \q!TI x
for(int i=0;i<nStartPos.length;i++) WqCER^~'>
{ pK>/c>de
nStartPos = input.readLong(); =(c.8d
nEndPos = input.readLong(); -~~R?,H'Z_
} U CFw+
input.close(); h^WMv *2
} ]w-W
catch(IOException e){e.printStackTrace ();} PK{FQ3b2{
catch(Exception e){e.printStackTrace ();} )P+<=8@a
} ]d|M@v~c4
R5},E
#{)mr [c|
private void processErrorCode(int nErrorCode) -0CL#RzKR
{ F5UHkv"K&O
System.err.println("Error Code : " + nErrorCode); [ f<g?w
} 4w 7vgB
KeyHxU=?
La7}zXx
//停止文件下载 BT -Y9j
public void siteStop() tB}W )Eb
{ U~zy;MT
bStop = true; CX{M@x3m
for(int i=0;i<nStartPos.length;i++) t08[3Q&
fileSplitterFetch.splitterStop(); g+&wgyq5
"KC3+:tm
jW| ,5,43
} ?^8.Sa{
} p[!9objU
//负责部分文件的抓取 4q@[k:'
**FileSplitterFetch.java I.2>d_^<
*/ Q"LlBp>t|#
package NetFox; _$}@hD*R~
0@&;JMh6<
$S/WAw,/
import java.io.*; !.q#X^@>L
import java.net.*; wv%UsfD
0*uJS`se6Z
^zG!Z:E
public class FileSplitterFetch extends Thread { ']X0g{%
m[N&UM#
q.ppYXJUXi
String sURL; //File URL \w$e|[~
long nStartPos; //File Snippet Start Position !83 N#Y_Mz
long nEndPos; //File Snippet End Position ]jmZ5h#[
int nThreadID; //Thread's ID ,mD$h?g
boolean bDownOver = false; //Downing is over PDh!B_+
boolean bStop = false; //Stop identical 2:[G4
FileAccessI fileAccessI = null; //File Access interface Sc]h^B^7
f[OJqk
FT gt$I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )Z:maz
{ MLDAr dvK
this.sURL = sURL; Zc9S[ivq
this.nStartPos = nStart; +sd':vE
this.nEndPos = nEnd; U!lWP#m
nThreadID = id; fL&e^Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &b19s=Z,
} ?/Aql_?3
4`"Q!T_'
:|ytw=3>
public void run() /hGu42YG
{ 1Zp^X:(
while(nStartPos < nEndPos && !bStop) cgQ2Wo7tCq
{ V4gvKWc
mO0#xY_z
*^\u%Ir"
try{ Vgj[m4l
URL url = new URL(sURL); 1!ijRr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aU] nh. a
httpConnection.setRequestProperty("User-Agent","NetFox"); c 8|&Q
String sProperty = "bytes="+nStartPos+"-"; 0gKSjTqo
httpConnection.setRequestProperty("RANGE",sProperty); ~Z97L
Utility.log(sProperty); MG,?,1_ &
t$uj(y>
z8PV&o
InputStream input = httpConnection.getInputStream(); W%#LHluP
//logResponseHead(httpConnection); Q>/[*(.Wd
%BkPkQA
C9`x"$
byte[] b = new byte[1024]; 5PKdMEK|q
int nRead; E{B40E~4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =XUt?5
{ q0_Pl*
nStartPos += fileAccessI.write(b,0,nRead); wH qbTA
//if(nThreadID == 1) YtT:\#D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rf2-owWN
} 4?7OP t6
]=5D98B
l]P3oB}Yo
Utility.log("Thread " + nThreadID + " is over!"); RLF]Wa,
bDownOver = true; -s6;IoG/
//nPos = fileAccessI.write (b,0,nRead); Snas:#B!
} g6q67m<h
catch(Exception e){e.printStackTrace ();} ] 2lhJ
} @p7*JLO
} y]%Io]!d
!*B1Eo--cN
]1KF3$n0
//打印回应的头信息 4--[.j*W
public void logResponseHead(HttpURLConnection con) n{.SNipU
{ OQsF$%*
for(int i=1;;i++) h4? 'd+K
{ &28%~&L
String header=con.getHeaderFieldKey(i); d-$/C| J
if(header!=null) E`UEl$($
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;rh@q4#
Utility.log(header+" : "+con.getHeaderField(header)); ?(j:F2dU~
else " [K>faV
break; oyo V1jO
} B3&`/{u
} +S}/6dg
^y&sKO
1bJrEXHXy
public void splitterStop() #ZpR.$`k
{ 7-MkfWH2b6
bStop = true; AU^5N3%j
} !qVnziE,,
8 gzf$Oc
p EbyQ[
} S9S%7pE
xy1R_*.F^T
VpmD1YSn
/* G>c:+`KS
**FileAccess.java ,hXhcfFl
*//文件访问(定位，写) Ln5g"g8gb%
package NetFox; #x5?RHX56
import java.io.*; 5KDN8pJN
"\M^jO
kG$U
public class FileAccessI implements Serializable{ vTUhIFa{
H~r":A'"*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "~/O>.p
RandomAccessFile oSavedFile; $23dcC*hI
long nPos; $|bdeQPr\
&>%9JXU
R3%&\<a)9
public FileAccessI() throws IOException |4|j5<5
{ l^E)XWd
this("",0); O4fl$egQU
} *.F4?i2D
use` y^c
ptEChoZ6
public FileAccessI(String sName,long nPos) throws IOException h1.<\GO
{ #=\nuT'oy
oSavedFile = new RandomAccessFile(sName,"rw"); /#I~iYPe
this.nPos = nPos; uiIS4S_
oSavedFile.seek(nPos); L9":=
} _iZ_.3Ip
ky-9I<Z,,
r5S5;jL%t
public synchronized int write(byte[] b,int nStart,int nLen) Z1ZjQt#~+
{ /32x|Ow# 1
int n = -1; Z. G<'
try{ wxSJ
oSavedFile.write(b,nStart,nLen); E+e:UBeUV
n = nLen; Doc_rQYku
} e.jbFSnA
catch(IOException e) V+&C_PyC
{ ~V6wcXd
e.printStackTrace (); n(tx'&U"R
} L:E?tR}H
eT6T@C](
FA3YiX(-e
return n; !omf>CW;ud
} 0JM`*f%n
H$={i$*,Y
M"Q{lR
} ];8S<KiS~
.DG`~Fpk
_[t:Vme}v
/* 7@uhw">mX
**SiteInfoBean.java @Xg5E
*/ o{?Rz3z
package NetFox; 4RoE>m1[G
g,]GzHV1
Ek%mX"
public class SiteInfoBean { XlDN)b5v{
`4kVe= {
GP{$w_'!J0
private String sSiteURL; //Site's URL {IA3`y~
private String sFilePath; //Saved File's Path ::R5F4
private String sFileName; //Saved File's Name \qj(`0HG
private int nSplitter; //Count of Splited Downloading File SM8Wg>
AD^Q`7K?uR
>JckN4v
public SiteInfoBean() [h[@?8vB
{//nSplitter的缺省值为5 !}PZCbDhL
//default value of nSplitter is 5 ?3=y]Vb+
this("","","",5); ^R7|x+
} ^9fY%98
%v)O!HC}
h1REL^!c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -fCR^`UOS
{ ^e\H V4s
sSiteURL= sURL; Zb}U 4
sFilePath = sPath; r"xs?P&/$
sFileName = sName; f6k=ew
this.nSplitter = nSpiltter; hYB3tT
&.1qixXIr
PB(I3R9
} $QB/n63
<kOdd)X
PQJw"[N/YM
public String getSSiteURL() <`'T#e$
{ ;(r,;S_`0
return sSiteURL; 5u=>~yK+
} X([p0W 9V(
:`>bh
{j[a'Gb
public void setSSiteURL(String value) 92XG|CWX
{ oFL7dL
sSiteURL = value; Gw-y6e'|Y
} T7R,6qt
r%\%tz'`j
eY\w?pT2
public String getSFilePath() $q*hE&x Qd
{ C8t;E`
return sFilePath; e82xBLxR%
} =M9;`EmC
A"i$.dR{
ZgA+$}U)uW
public void setSFilePath(String value) .oH)eD
{ .OcI.1H[
sFilePath = value; ex6QHUQ
} 2$TwD*[
8h,=yAn5
.s-*aoj
public String getSFileName() D=@bPB>
{ hg2UZ% Y
return sFileName; e?_uJh"
} = P$Q;d
W$xW9u8@+(
F4PWL|1
public void setSFileName(String value) t Z@OAPRx
{ {4eI}p<
sFileName = value; =A{s,UP
} Pl\NzB,`
Ruv`yfQ
)~-r&Q5d
public int getNSplitter() 7sq15oL
{ z-N N(G+
return nSplitter; >!MRk[@ V-
} xSrjN
7:e5l19 uI
Y_nl9}&+C0
public void setNSplitter(int nCount) %l[]n;*$
{ sA2esA@C<o
nSplitter = nCount; W:>XXUU
} yT|44 D2j
} N qS]dH61
r;_*.|AH
TeRH@oI
/* _$_,r H
**Utility.java ,H>'1~q
*/ mO2u9?N
package NetFox; _%G;^ b
]Z?jo#F
S!66t?vHB
public class Utility { EV@yJ]
I,W`s
dkg| kw'
public Utility() uCoy~kt292
{ A|YiSwyy
RTr"#[
XhUVDmeUMb
} XtqhK"f%
,\T7{=ZG\!
//线程睡眠 A1n4R
public static void sleep(int nSecond) _+,>NJ
{ i0F6eqe=J
try{ Qs ysy
Thread.sleep(nSecond); j'`-3<k
} Clb7=@f
catch(Exception e) m-bu{
{ &"(zK"O
e.printStackTrace (); T:SqENV
} ?&!e f{
} g}d[j I9
3wg1wl|
//日志 6O_l;A[=1
public static void log(String sMsg) NOmFQ)/ &
{ nNf*Q r%Z
System.err.println(sMsg); *7w!~mn[m
} aNBwb9X
B=~uJUr
<G'M/IR a
public static void log(int sMsg) md `=2l
{ zkquXzlgB
System.err.println(sMsg); >qBJK)LHOv
} -]t>'Q?
} 9/_~YY=/h
:D4'x{#H
]FgKL0
/* iBwM]Eyv.
**TestMethod.java r uIgoB
*/ Xzl$Qc
package NetFox; Xck`"RU<xA
=;(L$:l~
~E/=nv$
public class TestMethod { v#EFklOP
^7a@?|,q8
k136n#KN1
public TestMethod() Ri\\Yb
{ ///xx/weblogic60b2_win.exe f!H/X%F
try{ H%>^_:h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Lrmhr3 w5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); AiB]A}
SiteFileFetch fileFetch = new SiteFileFetch(bean); *Nfotv
fileFetch.start(); =WHI/|&
} f[ KI T
catch(Exception e){e.printStackTrace ();} o/ 7[ G
{$#88Qa\-
=K_&@|f+B
} [] el4.J,
lF t^dl^
?C- ju8]|
public static void main(String[] args) U1(cBY
{ v!$:t<-5N
new TestMethod(); mT #A?C2
} E]}_hZU
} `F]
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