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)); ^}J<)}Q
} (Ux[[
for(int i=0;i<nEndPos.length-1;i++) }w#F6
{ 6(Vhtr2(*
nEndPos = nStartPos[i+1]; e gI&epN
} `%Q&</X
nEndPos[nEndPos.length-1] = nFileLength; _B3zRO
} zd.'*Dj
} aZ6'|S;
`^x9(i/NE
+pz}4M`
//启动子线程 t!jYu<P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Yk'm?p#~
for(int i=0;i<nStartPos.length;i++) J1X~vQAe
{ 0\Y1}C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JGis"e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &))\2pl
nStartPos,nEndPos,i); ^&Q<tN7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i'=2Y9S}
fileSplitterFetch.start(); aBxiK[[`
} f}iU& 3S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >?I/;R.-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rEM#D]k
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", epkD*7
nEndPos = " + nFileLength); W:vr@e6
// fileSplitterFetch[nPos.length-1].start(); FshC )[w,
)c+k_;t'+
pawl|Z'Ez
//等待子线程结束 mlB~V3M'G
//int count = 0; id?E)Jy
//是否结束while循环 "(f`U.
boolean breakWhile = false; "}zt`3
^_W40/c3
MA* :<l
while(!bStop) nQ-mmY>#
{ Qnt5HSSt
write_nPos(); Oaa"T8t
Utility.sleep(500); w7 *V^B
breakWhile = true; z:}nBCmLV
/iG7MC\`
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for(int i=0;i<nStartPos.length;i++) cP rwW6
{ q7_+}"i
if(!fileSplitterFetch.bDownOver) {v,)G)obWw
{ [_.n$p-
breakWhile = false; J'Sm0
break; +TSSi em
} !Z|($21W
} ;dZMa]X0
if(breakWhile) r4Q|5kT*i
break; VteEDL/w
eV2mMSY
qZ+H5AG2
//count++; Q2QY* A
//if(count>4) ahGT4d`)9
// siteStop(); uM S*(L_
} *9D!A
DNP@A4~
DQ80B)<O
System.err.println("文件下载结束！"); 7x k|+!
} ^+/kr/
catch(Exception e){e.printStackTrace ();} e.vtEQV9
} $NG++N
NX,-;v
s([dGD$i
//获得文件长度 L:R<e#kgS
public long getFileSize() ^3~e/PKM
{ ,hRN\Kt)p
int nFileLength = -1; )jDJMi_[
try{ z&}-8JykH
URL url = new URL(siteInfoBean.getSSiteURL()); Im?LIgt$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n}nEcXb
httpConnection.setRequestProperty("User-Agent","NetFox"); VaLs`q&3>
.*5Z"Q['G
Es4qPB`g.
int responseCode=httpConnection.getResponseCode(); HdX2YPYn;
if(responseCode>=400) E>uVofhml
{ #R&H&1
processErrorCode(responseCode); \'v(Xp6
return -2; //-2 represent access is error AkBMwV
} z`3( ,V
Wf26
QlZ@ To
String sHeader; )"<8K}%!
@N.jB#nEb
ftbpqp'
for(int i=1;;i++) ~Y!kB:D5;~
{ &^.57]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); EqB)sK/3
//Utility.log(in.readLine()); zGlZ!t:
sHeader=httpConnection.getHeaderFieldKey(i); cj$6
if(sHeader!=null) 9Kv|>#zff
{ qUJ aeQ
if(sHeader.equals("Content-Length")) Gc,_v3\
{ 8|g<X1H{M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,xi({{L*
break; sM2MLh'D
} X$n(-65
} 4=<*Vd`p
else <[~,uR7
break; F7}-!
} a2@c%i
} au@a8MP
catch(IOException e){e.printStackTrace ();} Y3U9:VB
catch(Exception e){e.printStackTrace ();} hpbf&S4
Ctu?o+^;z
{8RFK4! V@
Utility.log(nFileLength); V-yUJ#f8[
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GZ#aj|
return nFileLength; E8[T
} *ZCn8m:-+
_8?o'<!8?^
/F/;G*n
//保存下载信息（文件指针位置） _=XX~^I,
private void write_nPos() ^"8wUsP
{ 0#p/A^\#7M
try{ 5]Ajf;W\
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5g5'@vMN
output.writeInt(nStartPos.length); dl]#
for(int i=0;i<nStartPos.length;i++) Q /x8 #X
{ rSXzBi{
// output.writeLong(nPos); 8MwK.H[U
output.writeLong(fileSplitterFetch.nStartPos); ()T[$.(
output.writeLong(fileSplitterFetch.nEndPos); u{H?4|'(
} BRRj$)u
output.close(); R!\EKH
} kLSrj\6I[
catch(IOException e){e.printStackTrace ();} n$L51#'
catch(Exception e){e.printStackTrace ();} #\rwLpC1u
} +K",^6%1
)u:Q) %$t
g{k1&|
//读取保存的下载信息（文件指针位置） tfO#vw,@
private void read_nPos() %|W.^q
{ A#wEuX=[
try{ =3xE:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )(M7lq.e7
int nCount = input.readInt(); v-j3bB
nStartPos = new long[nCount]; YvL?j
nEndPos = new long[nCount]; 6aft$A}XnD
for(int i=0;i<nStartPos.length;i++) knp>m,w
{ )$GIN/i
nStartPos = input.readLong(); [IZM.r`Z
nEndPos = input.readLong(); X@N$Z{
} I,@r5tKo
input.close(); 2!1.E5.I
} vsB*rP=
catch(IOException e){e.printStackTrace ();} XKOUQc4!R
catch(Exception e){e.printStackTrace ();} SuBeNA[&
} XUMX*
oih5B<&f#
zk_Eb?mhwV
private void processErrorCode(int nErrorCode) ~`8hwR1&z
{ -;(Q1)&
System.err.println("Error Code : " + nErrorCode); +!t}
} Nil}js27
>c8GW >\N
4Aes#{R3v
//停止文件下载 -[7O7'
public void siteStop() RSfM]w}Hq#
{ B0}~G(t(
bStop = true; >B -q@D
for(int i=0;i<nStartPos.length;i++) 's?Ai2=#
fileSplitterFetch.splitterStop(); QWnndI_4p
<~emx'F|
@ T;L$x
} 9W7#u}Z
} @`"AHt
//负责部分文件的抓取 w?vVVA
**FileSplitterFetch.java ihe(F7\U
*/ *O$CaAr\s
package NetFox; q z&+=d@
,<,:8B
F!!N9VIC
import java.io.*; 4'pS*v
import java.net.*; 10[Jl5+t
OKOu`Hz@
-4#2/GXNO
public class FileSplitterFetch extends Thread { l]!9$
h[tix:
`b5 @}',
String sURL; //File URL i8X`HbmN
long nStartPos; //File Snippet Start Position 0[A9b,MMVO
long nEndPos; //File Snippet End Position SjEAuRDvUz
int nThreadID; //Thread's ID B6P|Z%E;D6
boolean bDownOver = false; //Downing is over er.L7
boolean bStop = false; //Stop identical F51.N{'
FileAccessI fileAccessI = null; //File Access interface `\Ku]6J]5
#.B"q:CW*P
pI[ZBoR~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException R\Z:n*
{ ~|Y>:M+0Z
this.sURL = sURL; u'A#%}3
this.nStartPos = nStart; ~`#-d ^s:
this.nEndPos = nEnd; %bXtKhg5eJ
nThreadID = id; 0o&MB Dp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zW |=2oX2
} ^}yg%+
+A_J1iJ<
xvLn'8H.
public void run() $gle8Z-
{ 'Yy&G\S
while(nStartPos < nEndPos && !bStop) #1-xw~_
{ ~q0*"\Ff
^,Ydr~|T
ITuq/qts]A
try{ ewsKH\#
URL url = new URL(sURL); TB6m0qX(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oSb, :^Wl
httpConnection.setRequestProperty("User-Agent","NetFox"); y? (2U6c
String sProperty = "bytes="+nStartPos+"-"; 6X g]/FD
httpConnection.setRequestProperty("RANGE",sProperty); bucR">_p
Utility.log(sProperty); 1[nG}
uUR~&8ERX
{.e=qQ%P5)
InputStream input = httpConnection.getInputStream(); LS>G4 ]
//logResponseHead(httpConnection); 5wtTP ;P
JHn*->m
:bU(S<%M
byte[] b = new byte[1024]; bJr[I
int nRead; Jhkvd<L8`m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) iGXI6`F"
{ 7iC *Pr
nStartPos += fileAccessI.write(b,0,nRead); ?0*8RK
//if(nThreadID == 1) _,h@:Xij
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kQdt}o])
} ["<nq`~
omZO+=8Q
vy@rQC %9
Utility.log("Thread " + nThreadID + " is over!"); F-Z%6O,2
bDownOver = true; 8Q`WB0E<|
//nPos = fileAccessI.write (b,0,nRead); $e%2t^ i.g
} d=.2@Ry
catch(Exception e){e.printStackTrace ();} Q<tu)Qo
} &FdWFt=X
} =x#FbvV
[ANuBNF
"LhUxnll
//打印回应的头信息 VUU]Pu &
public void logResponseHead(HttpURLConnection con) > Vb@[
{ yWPIIWHx!
for(int i=1;;i++) tEd.'D8 s
{ qgt[~i*
String header=con.getHeaderFieldKey(i); z:Sigo_z[
if(header!=null) Kz8:UG(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); iSRpfU
Utility.log(header+" : "+con.getHeaderField(header)); UQCo}vM
else fr6^nDY
break; wHjLd$ +o
} ]T! }XXK
} *TW=/+j
Q3W#`6jpF
2U kK0ls
public void splitterStop() 7"X>?@
{ /{2*WI;
bStop = true; Id'RL2Kq*&
} .@ C{3$,VG
=`n]/L"Q
t,)N('m}=
} I&9S;I$
2],_^XBvB
tL SN`6[:
/* _:n b&B
**FileAccess.java Gnm4gF!BI
*//文件访问(定位，写) k#TYKft
package NetFox; hlZ@Dq%f
import java.io.*; :m=m}3/:
c47")2/yO
Dz=k7zRg"
public class FileAccessI implements Serializable{ G}@#u9
uNbH\qd=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h5z)Lc^
RandomAccessFile oSavedFile; ulHn#)
long nPos; 0XwHP{XaO
7DW]JK l
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public FileAccessI() throws IOException a>4uiFiv
{ M/PFPJ >`
this("",0); SDG-~(Y
} ?zJpD8e
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fHrt+_Zn|
public FileAccessI(String sName,long nPos) throws IOException -37a.
{ (LvS :?T}
oSavedFile = new RandomAccessFile(sName,"rw"); /z7VNkD
this.nPos = nPos; )o1eWL}
oSavedFile.seek(nPos); Q0?\]2eet9
} +^aFs S
3T\l]? z
eC DIwB28
public synchronized int write(byte[] b,int nStart,int nLen) vP%tk s+.
{ zHWSE7!
int n = -1; ,?UM;^
try{ |as!Ui/J/
oSavedFile.write(b,nStart,nLen); Z.L?1V8Q1
n = nLen; yAT^VRbv
} }F6<w{|
catch(IOException e) uxn)R#?
{ ubMOD<
e.printStackTrace (); ;^ wd_
} .@)mxC:\K9
seFGJfN\?f
xVB;s.'!
return n; I:&/`K4,x,
} sML=5=otx
kB:Uu}(=N
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} 6\7ncFO3
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h!@|RW&}qX
/* s1Ok|31|
**SiteInfoBean.java s>_V
*/ n>3U_yt6b
package NetFox; uf<@ruN
<oKGD50#
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public class SiteInfoBean { -hcS]~F
5V[oE\B
~fl@ 2
private String sSiteURL; //Site's URL %)jxW{
private String sFilePath; //Saved File's Path ?PA$Ur21lw
private String sFileName; //Saved File's Name 7`vEe'qz
private int nSplitter; //Count of Splited Downloading File z't??6
[%~ :@m
{_N,=DQ!
public SiteInfoBean() |@?%Ct
{//nSplitter的缺省值为5 M}:=zcZ l
//default value of nSplitter is 5 r;9 r!$d
this("","","",5); \]Kh[z0"
} rD?L
q/3ziVd7p
3<=,1 cU
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c0c|z Ym
{ 7g=2Z[o
sSiteURL= sURL; N#V.1<Y
sFilePath = sPath; eAUcv`[#p
sFileName = sName; O1%pxX'`S
this.nSplitter = nSpiltter; kp?w2+rz
<9ig?{'
[=O/1T
} bn 6WjJ~Z+
NW~z&8L
Z UKf`m[
public String getSSiteURL() 4%WzIzRb
{ Qjx?ri//
return sSiteURL; }nt* [:%
} _AV1WS;^^8
MRU7W4W-~/
7\_o.(g#-
public void setSSiteURL(String value) I8oo~2Qw
{ }:: S0l
sSiteURL = value; VxP&j0M>
} wB'zuPAK6
8x`.26p
%h1N3\y9i(
public String getSFilePath() I%|>2}-_U
{ pEECHk
return sFilePath; Y_`-9'&
} ' |-JWH
L lqM c
XC{eX&,2x
public void setSFilePath(String value) .4.b*5
{ 9nu3+.&P
sFilePath = value; f7Ul(D:j\
} "CiTa>x
3_JCU05H}
0$r^C6}f
public String getSFileName() t1E[uu,V8
{ rD>*j~_+P
return sFileName; =PGs{?+&O
} 4Llo`K4
L(GjZAP
O25lLNmO
public void setSFileName(String value) d1[ZHio2c?
{ x8GJY~:SW
sFileName = value; Y8flrM2CwG
} SkU9ON
tTd\|
+{sqcr1G
public int getNSplitter() mf'V)
{ G "P4-
return nSplitter; G[jW<'f
} Z"unF9`"1
;c$J=h]
z3?o|A}/W
public void setNSplitter(int nCount) 1}~(Yj@f%
{ .F+@B\A<
nSplitter = nCount; FLEo*9u>b
} @JdZ5Q
} jt+iv*2N>
a&vY!vx3
S*yjee<@
/* v%Wx4v@%SE
**Utility.java ,@5I:X!rR
*/ JU&+c6>
package NetFox; Z0l+1iMx
nB .G
1'?4m0W1
public class Utility { Y`?-VaY
1^gl}^|B
8V~vXnkM
public Utility() bJs9X/E
{ DK}"b}Fvq
}f2r!7:x
!>:?rSg*
} y+7PwBo%e
NVRLrJWpp
//线程睡眠 av~5l4YL
public static void sleep(int nSecond) |fo0
{ Jec'`,Y
try{ K$d$m <
Thread.sleep(nSecond); J`2"KzR0w"
} [n}T|<
catch(Exception e) &\_iOw8
{ 64 5z#_}C$
e.printStackTrace (); f7}*X|_Y
} CD8}I85K
} }}<z/zN&^
aM;W$1h
//日志 4f<$4d^md
public static void log(String sMsg) =z8f]/k*>
{ +]Y,q w
System.err.println(sMsg); 9+pmS#>_
} {^N[("`
QPq7R
0Zg%+)iy@
public static void log(int sMsg) ZWS`\M
{ N 8-oY$*
System.err.println(sMsg); MuSUKBhM
} /Ju;MeE9
} PsZ >P|e1
2;?I>~
e zOj+vz
/* J4\qEO
**TestMethod.java bAx?&$
*/ Hik3wPnp
package NetFox; }C|dyyr
l(Q?rwI8Y
-neKuj
public class TestMethod { M4W5f#C5Ee
p l&Muv
0c#/hFn
public TestMethod() ,tg0L$qC
{ ///xx/weblogic60b2_win.exe CH<E,Z C1T
try{ 42qYg(tZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZR'H\Z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q6r7.pk"SU
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2j&AiD
fileFetch.start(); ]H1I,`=@
} T|6a("RL
catch(Exception e){e.printStackTrace ();} )=etG
P$-X)c$&
Q0ON9gqqv
} VzKW:St
y? co|
3F<VH
public static void main(String[] args) %p0xM
{ Y"wUt &
new TestMethod(); X'"SVO.
} ze]h..,]K
} 5O6hxcMjT
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