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)); d5NE:%K
} )w~1VcnJEp
for(int i=0;i<nEndPos.length-1;i++) tA^+RO4
{ X{Fr
nEndPos = nStartPos[i+1]; S{?l/*Il*_
} aGBd~y@e
nEndPos[nEndPos.length-1] = nFileLength; 'z^'+}iyv
} xT+#K5
} &c 2Qa
LtH j
r95,X!
//启动子线程 e`co:HO`#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e/cHH34
for(int i=0;i<nStartPos.length;i++) `+T 2IPN
{ <o9AjASv\,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $@@ii+W}\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :-O$rm
nStartPos,nEndPos,i); |fywqQFq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bfpeK>T
fileSplitterFetch.start(); 3b\s;!
} ]?)uYot
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c&1_lI,tH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (V&8 WN
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pj<aMh
nEndPos = " + nFileLength); Dt<MEpbur
// fileSplitterFetch[nPos.length-1].start(); $K+|bb
{ TI,|'>5[
+_/ys!
//等待子线程结束 L){V(*K '
//int count = 0; c]Gs{V]\
//是否结束while循环 7TEpjSuF
boolean breakWhile = false; @`)>-k
%f'=9pit
Xq )7Im}?
while(!bStop) !@])Ut@tN
{ 4lR+nmAZ
write_nPos(); gaQ E'qp>
Utility.sleep(500); S!#5
breakWhile = true; 4i.&geXA.
+L"F]_?
x&^Xgi?
for(int i=0;i<nStartPos.length;i++) za}Kd^KeB
{ V)Oot|
if(!fileSplitterFetch.bDownOver) Y-Q)sv
{ (&NLLrsio
breakWhile = false; k~so+k&=b
break; H>D sAHS
} Y@:l!4DI
} cLp_\\
if(breakWhile) 5=8v\q?)c
break; G~DHNO6
50dN~(;p
[T4{K&
//count++; JBA{i45x
//if(count>4) xv Xci W
// siteStop(); 8\9W:D@"x
} r>! @Z2%s
9(qoME}>=
ftcLP
System.err.println("文件下载结束！"); q+4dHS)x
} 5x|$q kI
catch(Exception e){e.printStackTrace ();} p#Po?
} Q=d:Yz":S
eaNfCXHDN
)X," NJG
//获得文件长度 -W.-m2:1
public long getFileSize() 3 ^x&G?)
{ I$S*elveG
int nFileLength = -1; jl}!UG
try{ Xs|d#WbX
URL url = new URL(siteInfoBean.getSSiteURL()); K|\0jd)N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n^$Q^[:Z
httpConnection.setRequestProperty("User-Agent","NetFox"); 0[fBP\H"Wr
@`+\vmfD
^7ID |uMr
int responseCode=httpConnection.getResponseCode(); ^!C
if(responseCode>=400) x^c,cV+*
{ c%O97J.5b
processErrorCode(responseCode); }"nm3\Df
return -2; //-2 represent access is error !SE
} `n-/~7
J"< h#@`
FeS ,TQ4j
String sHeader; }f_@@#KB?
^t71${w##
J @~g>
for(int i=1;;i++) o3\^9-jmp
{ j@#RfVx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y{<js!au
//Utility.log(in.readLine()); Z ztp %2c
sHeader=httpConnection.getHeaderFieldKey(i); y${`W94
if(sHeader!=null) -hfkF+=U'
{ suIYfjh
if(sHeader.equals("Content-Length")) o<p4r}*AVJ
{ %-fS:~$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); A@?-"=h}
break; p<h(
} bC"h7$3
} +~YoP>
else 2Mq@5n
break; J=8Y D"1
} z>0$SBQ-
} cZ !$XXA`
catch(IOException e){e.printStackTrace ();} }@jJv||
catch(Exception e){e.printStackTrace ();} qhG2j;
">_|!B&wb^
^K::g)
Utility.log(nFileLength); ^\ln8!;
^8bc<c:P
jj;TS%
return nFileLength; %Qb}z@>fJk
} D3,)H%5.y
jTNt!2 :B
ZwY mR=
//保存下载信息（文件指针位置） yK9EHJ$
private void write_nPos() k:iy()n[
{ /qwY/^
try{ !mWm@}Ujg
output = new DataOutputStream(new FileOutputStream(tmpFile)); _<2{8>EVf
output.writeInt(nStartPos.length); AB0}6g^O
for(int i=0;i<nStartPos.length;i++) ~.J*_0~Ze
{ 6vTnm4
// output.writeLong(nPos); gaNe\
output.writeLong(fileSplitterFetch.nStartPos); 8"NPj0
output.writeLong(fileSplitterFetch.nEndPos); {/N8[?zML
} YMNLn9
output.close(); Wi5Dl=
} X{i>Q_8>
catch(IOException e){e.printStackTrace ();} hyJ&~i0P{J
catch(Exception e){e.printStackTrace ();} NOoF1kS+
} R=48:XG3/K
=d<~:!)
m+7%]$
//读取保存的下载信息（文件指针位置） )+Z.J]$O-
private void read_nPos() b&QI#w
{ +\dKe[j{g
try{ C2zKt/)A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); FYu30
int nCount = input.readInt(); qf ]le]J
nStartPos = new long[nCount]; I*JJvqh
nEndPos = new long[nCount]; E@)'Z6r1
for(int i=0;i<nStartPos.length;i++) vaHtWz!P
{ ;gu4~LQw
nStartPos = input.readLong(); |9.J?YP8 (
nEndPos = input.readLong(); _I3"35a
} /pU`-
input.close(); B<Cg_C
} 2'OY,Ooe
catch(IOException e){e.printStackTrace ();} (E,[Ad,$
catch(Exception e){e.printStackTrace ();} Unq~lt%2
} }M"])B I
'qde#[VB
VM&Ref4
private void processErrorCode(int nErrorCode) Y}q~Km
{ W?!rqo2SP
System.err.println("Error Code : " + nErrorCode); Hi$N"16A5z
} LH @B\ mS
iFcSz
~Al3Dv9x
//停止文件下载 }wBpBw2J
public void siteStop() ZdY$NpR,
{ Btr>ek
bStop = true; Hd7Vp:KM
for(int i=0;i<nStartPos.length;i++) _akjgwu
fileSplitterFetch.splitterStop(); v+trHdSBYE
cUd>ahv
8'qlg|{!~
} j"pyK@v2B
} 5! +{JTXa
//负责部分文件的抓取 .V}bfd[k$
**FileSplitterFetch.java =;Co0Q`
*/ XhWo~zh"
package NetFox; lk81IhI
\Nf[8n#{
(|<+yQ,@>
import java.io.*; cH:&S=>h
import java.net.*; kz("LI]
'L9hM.+
+eKLwM
public class FileSplitterFetch extends Thread { #4"eQ*.*"
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(~5]1S}F
String sURL; //File URL umAO&S.+M
long nStartPos; //File Snippet Start Position 8cMX=P
long nEndPos; //File Snippet End Position <s|.2~
int nThreadID; //Thread's ID ci:|x =
boolean bDownOver = false; //Downing is over |)0Ta9~
boolean bStop = false; //Stop identical <}c7E3Uc
FileAccessI fileAccessI = null; //File Access interface vpdPW%B
XN?my@_HpM
:P%?!'M
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mMWhUr
{ rFm?Bu
this.sURL = sURL; c(b`eUOO
this.nStartPos = nStart; Bf+~&I#E
this.nEndPos = nEnd; -ULgVGYKK
nThreadID = id; ![vy{U.:`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L*4=b (3
} X_bB6A6
t,0}}9%?
\h0+` ;Q
public void run() +7 j/.R
{ Lc]hwMGR*
while(nStartPos < nEndPos && !bStop) KjF8T7%
{ %gSmOW2.c^
!Z{7X ^
JX&%5sn(
try{ v^p* l0r6:
URL url = new URL(sURL); 63$`KG3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZJhI|wRwD
httpConnection.setRequestProperty("User-Agent","NetFox"); 'gD./|Z0
String sProperty = "bytes="+nStartPos+"-"; []yIz1P=j
httpConnection.setRequestProperty("RANGE",sProperty); 28+{
Utility.log(sProperty); `fJ;4$4
+<V$G/"
BNr%Q:Q
InputStream input = httpConnection.getInputStream(); 5 I#-h<SG
//logResponseHead(httpConnection); d$E>bo-\
0a@tPskV
z.2UZ%:
byte[] b = new byte[1024]; rxJl;!7G
int nRead; [(TmAEON
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I4UsDs*BD
{ d>#X+;-k
nStartPos += fileAccessI.write(b,0,nRead); ? IlT[yMw
//if(nThreadID == 1) h. 4#C}> )
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yiH;fK+x
} o"P)(;
K)Z~ iBRM
At[SkG}b
Utility.log("Thread " + nThreadID + " is over!"); j b'M
bDownOver = true; "qZTgCOY2
//nPos = fileAccessI.write (b,0,nRead); FLkZZ\
} I.~=\%Z{
catch(Exception e){e.printStackTrace ();} ,qV7$u
} loBW#>
} QC]<`!
zJUT<%[U
$`vXI%|.
//打印回应的头信息 m@L>6;*
public void logResponseHead(HttpURLConnection con) If'N0^'W
{ < %<nh`D
for(int i=1;;i++) ~% `hh9]
{ 9ku|w#%I
String header=con.getHeaderFieldKey(i); z 3Z8vq
if(header!=null) E0!0 uSg&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); V}Q`dEk2r
Utility.log(header+" : "+con.getHeaderField(header)); k{|>!(Ax
else h:FN&E c}
break; R]>0A3P
} d:cOdm>,
} A%&lW9z7
~rXLb:
0Am\02R.C,
public void splitterStop() B_8JwMJu3
{ y0) mBCX
bStop = true; [L|vBr
} Zk|PQfi+
Y q|OX<i`K
Hxc>?
} `m"K_\w=/
8W7ET@`
}~0}B[Rf
/* Y$|KY/)H)
**FileAccess.java j~9Y0jz_
*//文件访问(定位，写) }y(cv}8Y
package NetFox; Ar_Yl|a
import java.io.*; W%9~'pXgB
h*Mi/\
q 4Ok$~"I
public class FileAccessI implements Serializable{ ]'>jw#|h
Go]y{9+(7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 I.SMn,N
RandomAccessFile oSavedFile; GFnwj<V+{
long nPos; m5P@F@
n#4T o;CS
z$/s` |]
public FileAccessI() throws IOException kaECjZ_&+
{ o##!S6:A
this("",0); E=,fdyj.
} P/k#([:2
2J3y 1
3YUF\L]yyw
public FileAccessI(String sName,long nPos) throws IOException mWLiXKnb
{ M3JV^{O/DV
oSavedFile = new RandomAccessFile(sName,"rw"); `bLJwJ7
this.nPos = nPos; Ca/N'|}^
oSavedFile.seek(nPos); ]4lC/&nm
} XF@34b5(
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[8acan+ 2l
public synchronized int write(byte[] b,int nStart,int nLen) 9sv#TT5V
{ T7Ju7_q}
int n = -1; ~eiD(04^r*
try{ 5pff}Ru`
oSavedFile.write(b,nStart,nLen); jF#Dc[*
n = nLen; d@Wze[M?0
} }p8iq
catch(IOException e) mK^E@uxN
{ 6J-=6t|
e.printStackTrace (); \t=#MzjR
} &C?4'e
VY=YI}E
8@FgvWC
return n; M%$-c3x
} `C^0YGO%
9R[PpE''
yRp&pUtb
} _0iV6Bj
<e@4;Z(h04
lpbcpB
/* 4#B56f8
**SiteInfoBean.java _@_EQ!=
*/ X LY>}r
package NetFox; 4i"fHVp8
gmiLjI
C+Wa(K
public class SiteInfoBean { lxR]Bh+
@)ls+}=Y
_]0<G8|Rv
private String sSiteURL; //Site's URL YlZ&4
private String sFilePath; //Saved File's Path @qF:v]=_@
private String sFileName; //Saved File's Name ,"?8
private int nSplitter; //Count of Splited Downloading File &hM7y7
hij 9r z
>``
public SiteInfoBean() [[ll4|
{//nSplitter的缺省值为5 "_+8z_
//default value of nSplitter is 5 p$Floubh]
this("","","",5); +'[/eW
} F84<='K
tU.~7f#+A
{]4Zpev
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) OgzKX>N`A
{ gA]3h8%w
sSiteURL= sURL; *(Z\"o!
sFilePath = sPath; JI&.d:
sFileName = sName; $h >rs
this.nSplitter = nSpiltter; ~bw=;xF{3
wF*9%K'E
:=:m4UJb
} AO(zl*4
v&sl_w/tn
#9HX"<5
public String getSSiteURL() M>{*PHze0
{ K d{o/R
return sSiteURL; ;O<-4$
} |[)pQGw
sy(.p^Z
]L k- -\
public void setSSiteURL(String value) qsYg%Z
{ DyUS^iz~o
sSiteURL = value; Q$Sp'
} Qs<L$"L1
*y|zF6
A,?6|g`q'
public String getSFilePath() {r#uD5NJ/
{ d@ ]N
return sFilePath; [<wpH0lNoy
} *rYPjk6g[
/^WOrMR
A~<cp)E
public void setSFilePath(String value) nL]eGC
{ 6$H`wDh#(&
sFilePath = value; _Ec"[xW
} {"|la;*I
_]L]_Bh
({cWb:+r
public String getSFileName() Us%g&MWdpb
{ uF[~YJ>
return sFileName; +&<k}Mz
} I |"'
60WlC0Y~u
fk\]wFj
public void setSFileName(String value) n8i: /ypB
{ *qFl&*h}
sFileName = value; ^,`]Q)P^
} 4hkyq>c}
02-% B~oP
n|B<rx?v
public int getNSplitter() |*l^<==
{ }-Jo9dNs
return nSplitter; =o'g5Be<F
} b)r;a5"<5
lWBewnLKE
LyG`q3@
public void setNSplitter(int nCount) `$vf9'\+
{ #L&/o9|
nSplitter = nCount; ~6+>2|wIS
} ^4et; F%
} ]&tcocq
7JBr{3;eS
6NSSuK3
/* d?V/V'T[
**Utility.java ^UFNds'q
*/ {~XAg~
package NetFox; VLoRS)
9~y:K$NO
>'jkL5l
public class Utility { sH]T1z
LZQG.
?A-f_0<0
public Utility() ScmwHid:\
{ FRXaPod
??("0U
ant2];0p
} #c~-8=
l8e)|MSh
//线程睡眠 { _Y'%Ggh
public static void sleep(int nSecond) \C{Zqo,
{ /)<kG(Z
try{ .kJu17!
Thread.sleep(nSecond); -z%->OUu
} KEf1GU6s
catch(Exception e) ;j+*}|!
{ xc7Rrh]}
e.printStackTrace (); '}-QZ$|*
} 9WV8ZP
} PH'n`D#
XV,ce~ro[
//日志 IYa(B+nB)
public static void log(String sMsg) e*d lGK3l
{ A+FQmLS
System.err.println(sMsg); ~yA^6[a=
} {aUv>T"c
We'=/!
?a'EkZ.dB
public static void log(int sMsg) :)h4SD8Y
{ PF+Or
System.err.println(sMsg); y.(m#&T
} *:`fgaIDa
} Nnoj6+b
-OnKvpeI
wNUcL*n
/* d@zxgn7o
**TestMethod.java Yu9VtC1
*/ XinKG<3!
package NetFox; _qh\
<N3~X,ch
V}Oz! O
public class TestMethod { KIKIag#
nP|ah~ q
ngk:q5Tp
public TestMethod() ^ (J%)&_\3
{ ///xx/weblogic60b2_win.exe Nz%pl!
try{ J|HV8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7Q,<h8N\5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u#Bj#y!
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]I]G3 e
fileFetch.start(); f lt'~fe
} 4ywtE}mp
catch(Exception e){e.printStackTrace ();} dP#7ev]'
gADqIPu]
.k#O[^~]
} dF|R`Pa2ML
1`l(H4
MYR\W*B'b
public static void main(String[] args) x@:98P
{ 8cRc5X
new TestMethod(); 9Vt6);cA-]
} jwI1 I{x
} mxe\+j#
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