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)); "thfd"-
} EMs$~CL4
for(int i=0;i<nEndPos.length-1;i++) BtU,1`El5
{ LoBKR c2t
nEndPos = nStartPos[i+1]; aL#b8dCy'
} B: {bmvy
nEndPos[nEndPos.length-1] = nFileLength; b-~`A;pr
} :4(7W[r6
} e5veq!*C?
yKDg ~zsh
2Q1* Xq{
//启动子线程 Zh3]bg5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3bE^[V8/
for(int i=0;i<nStartPos.length;i++) VMHiuBz:
{ $5il]D`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }"q1B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), eYsO%y\I
nStartPos,nEndPos,i); W{Nhh3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '-W p|A
fileSplitterFetch.start(); Y;-"Z
} zg8m(=k'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {/R4Q1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NbkWy
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", EWH'x$z_q
nEndPos = " + nFileLength); 7J$ ^R6rh
// fileSplitterFetch[nPos.length-1].start(); xvpS%MS
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&w/aQs~
//等待子线程结束 U$0#j
//int count = 0; r}*2~;:pW
//是否结束while循环 9H.E15B
boolean breakWhile = false; u7a4taM$d
0{AVH/S
9dKrE_zK:
while(!bStop) f$(w>B7..
{ .>CqZN,^
write_nPos(); {&K#~[)
Utility.sleep(500); [Hn+r&
breakWhile = true; p(f)u]1`
@X1>Wv|[
"b -KVZ
for(int i=0;i<nStartPos.length;i++) WGp81DNS|
{ 0m*0I>
if(!fileSplitterFetch.bDownOver) S1`+r0Fk~n
{ 0B3*\ H}5
breakWhile = false; w9.r`_-
break; Zu~ #d)l3N
} We9C9)0
} mE^6Zu
if(breakWhile) ''f
break; A:NsDEt
7cvbYP\<lv
hnE@+(d=qJ
//count++; $7|0{Dw
//if(count>4) o`G'E&
// siteStop(); {#Gr=iv~N
} <V>vDno\
tYmWze.j
[!bTko>rSB
System.err.println("文件下载结束！"); <niHJ*
} 3~Ipcr B
catch(Exception e){e.printStackTrace ();} %li'j|
} !f7}5/YC7v
ih1SN,/
=;@5Ue J
//获得文件长度 ??1V__w
public long getFileSize() aEX+M57k~
{ ?CmW{9O
int nFileLength = -1; -Frx{3
try{ 4fpz;2%
URL url = new URL(siteInfoBean.getSSiteURL()); B.&q]CAv-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z,DEBRT+
httpConnection.setRequestProperty("User-Agent","NetFox"); 0>E`9|
WOgbz&S?J
v\\Z[,dK
int responseCode=httpConnection.getResponseCode(); ]9A9q<lZ
if(responseCode>=400) ]^aece t
{ N],A&}30
processErrorCode(responseCode); O\lt!p3F
return -2; //-2 represent access is error K mL PWj
} 5^P)='0*
w6#hsRq[C
hnG'L*HooE
String sHeader; *W#x#0j
9>%f99n
PlBT H
for(int i=1;;i++) 'SOp!h$
{ ULQ*cW&;?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ApS/,cV
//Utility.log(in.readLine()); P8;|>OLZ)
sHeader=httpConnection.getHeaderFieldKey(i); W@pVP4F0xM
if(sHeader!=null) 2/>AmVM
{ VN`2bp>5I
if(sHeader.equals("Content-Length")) SjG=H%
{ 6 D~b9e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4[+n;OI
break; CS6,mX
} B6=8cf"i
} MdEZ839J
else roL~r`f`
break; GH^i,88
} =_Qt&B)
} c%i/ '<Afr
catch(IOException e){e.printStackTrace ();} ogjm6;
catch(Exception e){e.printStackTrace ();} xN2{Vi{ad
yrkd#m
R.>/%o
Utility.log(nFileLength); p,ZubRJ"
3-LO
[ &R-YQ@
return nFileLength; m<"1*d~
} uX`Jc:1q3
/ ^!(rHf
Kw925@W
//保存下载信息（文件指针位置） DB%=/ \U
private void write_nPos() Jq?ai8
{ ##R]$-<4dQ
try{ Ct"h.rD]
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8+gSn
output.writeInt(nStartPos.length); yUNl)E
for(int i=0;i<nStartPos.length;i++) \<;/)!Nmw
{ #T !YFMh;
// output.writeLong(nPos); "FG6R'
output.writeLong(fileSplitterFetch.nStartPos); 0jj }jw
output.writeLong(fileSplitterFetch.nEndPos); <8jn_6
} jY$|_o.4
output.close(); c;(}Ih(#
} mN~;MR;
catch(IOException e){e.printStackTrace ();} }Y<(1w
catch(Exception e){e.printStackTrace ();} =\oNu&Q^
} !m]76=@
d{9jd{ _#G
Dr`A4LnqY
//读取保存的下载信息（文件指针位置） PksHq77
private void read_nPos() @8V8gV?zm
{ Z>Sv[Ec
try{ (lt/ t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !X |Tf
int nCount = input.readInt(); %T1(3T{Li
nStartPos = new long[nCount]; t%N#Yh!
nEndPos = new long[nCount]; NhpGa@[D
for(int i=0;i<nStartPos.length;i++) n;2W=N?y
{ !aIIjWz]
nStartPos = input.readLong(); 2BRY2EF
nEndPos = input.readLong(); V{c n1Af
} Udd|.JRd
input.close(); X*d,z~k%*d
} 6;5}% B:#h
catch(IOException e){e.printStackTrace ();} xr.fZMOh4
catch(Exception e){e.printStackTrace ();} =BNmuAY7
} #l{qb]n]
J#'c+\B<2X
CUY2eQJ{U
private void processErrorCode(int nErrorCode) 2b3x|9o8
{ Y}e$5
System.err.println("Error Code : " + nErrorCode); W)j/[
} FDpNM\SR1l
' 71D:%p
qItj`F)d
//停止文件下载 b\6w[52m
public void siteStop() MUVp8!*@
{ s}/YcUK
bStop = true; OG}0{?
for(int i=0;i<nStartPos.length;i++) MPNBA1s
fileSplitterFetch.splitterStop(); 'B6D&xn'%&
8 I,(\<Xv
"64pVaT4
} %o*afd
} >W 8!YOc
//负责部分文件的抓取 .XYSO
**FileSplitterFetch.java [+ 1([#
*/ )mp0k%
package NetFox; uXtfP?3Vy
=C5[75z#+
[(UQQa=+
import java.io.*; uw;s](~E
import java.net.*; 8 rnr>Ee@
"f5u2=7 }
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public class FileSplitterFetch extends Thread { 3$WK%"%T
C.(<KV{b
,!u^E|24
String sURL; //File URL #YhKAG@|
long nStartPos; //File Snippet Start Position .KK"KO5k
long nEndPos; //File Snippet End Position :t9(T?2
int nThreadID; //Thread's ID tA'i-D&
boolean bDownOver = false; //Downing is over <>2QDI6_
boolean bStop = false; //Stop identical h`Y t4-Y
FileAccessI fileAccessI = null; //File Access interface /T*{Mo{B
RI-whA8+
o$Hc5W([Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DHm$gk
{ v)rN]b]
this.sURL = sURL; sOVaQ&+y
this.nStartPos = nStart; Lf7iOW9U3
this.nEndPos = nEnd; ,]20I _
nThreadID = id; x{RTI#a.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $"x(:
} dp_J*8
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5%,n[qj4IT
public void run() .DCp)&m l;
{ }RW4
while(nStartPos < nEndPos && !bStop) $F\&?B1.
{ %Sxy!gGz%%
#`}g?6VHo
P,tN;c
try{ | ql!@M(p
URL url = new URL(sURL); vT3LhN+1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YQe @C
httpConnection.setRequestProperty("User-Agent","NetFox"); LOe!qt\&
String sProperty = "bytes="+nStartPos+"-"; 4Mg09
httpConnection.setRequestProperty("RANGE",sProperty); uodO^5"-
Utility.log(sProperty); 1gH5#_?
%3"3OOT7
V}@c5)(j
InputStream input = httpConnection.getInputStream(); E2%7v
//logResponseHead(httpConnection); H$\?D+xlf
hoSk
QIo|t!7F
byte[] b = new byte[1024]; kZF\V7k
int nRead; 2c9@n9Vx3a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {zmo7~=
{ qY#*zx
nStartPos += fileAccessI.write(b,0,nRead); ^W#[6]S
//if(nThreadID == 1) @yobT,DXi
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XTHrf'BU
} :GGsQ n
K\n %&w
0Wv9K~F
Utility.log("Thread " + nThreadID + " is over!"); Tz%l9aC
bDownOver = true; LhV4 ^\+
//nPos = fileAccessI.write (b,0,nRead); j>0S3P,
} G|Q}.v
catch(Exception e){e.printStackTrace ();} F-_RL-hbN%
} 0@3g'TGl
} -c|O!Lc-
@{t^8I#]
7+=j]+O
//打印回应的头信息 MS,H12h
public void logResponseHead(HttpURLConnection con) bYG}CO
{ L\hPw{)
for(int i=1;;i++) `1pri0!
{ o&I0*~sN
String header=con.getHeaderFieldKey(i); y]cx}9~
if(header!=null) VVCCPK^<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zIRa%%.i<
Utility.log(header+" : "+con.getHeaderField(header)); gU+BRTZ&x
else (Grj_p6O
break; F \} Kh3
} zXVQLz5
} @/|sOF;8W
MV=.(Zs
Fi*6ud\n!
public void splitterStop() r@s, cCK9?
{ ]l+2Ca:-[j
bStop = true; ub.pJJlC
} yu}4L'e
,{zvGZ|
MQ,$'Y5~H
} | b@?]M
|Zkcs]8M!
!K`;fp!
/* Xb6@;G"
**FileAccess.java vs6`oW"{#
*//文件访问(定位，写) /Rt/Efu
package NetFox; YMqL,&Q{1
import java.io.*; mc9$"
<-FZ-asem
E7*1QR{Q
public class FileAccessI implements Serializable{ ~49+$.2
Hi.JL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >@]E1Qfe
RandomAccessFile oSavedFile; ;'p0"\SV
long nPos; 73N%_8DH
a.w,@!7
#gsAwna3
public FileAccessI() throws IOException 1 4(?mM3
{ uY'Ib[H
this("",0); RZ?>>Ll6
} ?8vjHEE
_>3GNvS
G?jY>;P)
public FileAccessI(String sName,long nPos) throws IOException FVF:1DT
{ 2hU4g e?6
oSavedFile = new RandomAccessFile(sName,"rw"); zxwpS
this.nPos = nPos; a#G7pZX/I}
oSavedFile.seek(nPos); 3OM\R%M
} *?\2Ohp
_#N~$
GI6 EZ}.MZ
public synchronized int write(byte[] b,int nStart,int nLen) [nG/>Z]W
{ iW |]-Ba\
int n = -1; Az0Yt31=
try{ C5XCy%h
oSavedFile.write(b,nStart,nLen); M~ *E!
n = nLen; hoU&'P8
} Rzb663d
catch(IOException e) t'[vN~I'
{ JziMjR
e.printStackTrace (); U/jJ@8
} +cjNA2@
u&pLF%'EQ
pRt )B`#
return n; gvwR16N
} @^;\(If2
uOougSBV,
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} ^Jc~G~x4*
uP+ j_is
'n>|jw)
/* $g1p!
**SiteInfoBean.java JTz1M~
*/ q:?g?v
package NetFox; 0imz}Z]
uy`U1>
'# (lq5 c
public class SiteInfoBean { ?$r+#'asd(
3&2,[G04
U][.ioc
private String sSiteURL; //Site's URL bF B;N+>
private String sFilePath; //Saved File's Path xn6E f"
private String sFileName; //Saved File's Name QjZ}*p
private int nSplitter; //Count of Splited Downloading File NWoZDsu
T,H]svN5p
XP{ nf9&
public SiteInfoBean() ;gW~+hW^
{//nSplitter的缺省值为5 {P = {)
//default value of nSplitter is 5 ybYSz@7
this("","","",5); MTLcLmdO
} v,>q]! |a
br'~SXl
RA\H?1;8C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e3(0L I
{ n,AN&BZ
sSiteURL= sURL; 4)XN1r:
sFilePath = sPath; lg!1q8
sFileName = sName; .|iUDp6vz
this.nSplitter = nSpiltter; T-<^mX[}
;$|+H"g|
-u8@ .
} ?Bh}
Sb,{+Wk
]8H;LgM2
public String getSSiteURL() -lAA,}&+!
{ rylllJz|L:
return sSiteURL; Gg-<3z
} ` 0\hm`
xRaYm
v`v+M4upC
public void setSSiteURL(String value) ?]P&3UU>0z
{ {/ty{
sSiteURL = value; 71)HxC[6vA
} 2;kab^iv'
,,{Uz)>'W6
:uI}"Bp
public String getSFilePath() &/7GhZRt
{ k+s<;{
return sFilePath; Mq*Sp UR
} !N)oi$T%
Qh{=Z^r
gu"Agct4
public void setSFilePath(String value) VvoJ85
{ uIWCVR8`Y
sFilePath = value; 1) @Wcc.
} :X;8$.z
4vy!'r@
Hq%`DWus\
public String getSFileName() &"L3U
{ y"){?
return sFileName; (:hPT-1
} Gt 2rJ<>
}. ,xhF[
3w^q0/GD
public void setSFileName(String value) i\`[0dfY
{ {8UBxFIM(
sFileName = value; ^U`[P@T
} 0<^K0>lm p
Kh5:+n_X
KzM\+yC
public int getNSplitter() aV>w($tdd
{ xDVzHgbf
return nSplitter; -6
} @AyC0}
mFo6f\DHr`
ZNuyGo;
public void setNSplitter(int nCount) 7p~@S4
{ 2&=;$2?}
nSplitter = nCount; ]jy6C'Mp
} QU417EV'
} PHz/^p3F
%*/?k~53
=e ;\I/
/* 52:oe1-8
**Utility.java S&R~*
*/ 1nvs51?H
package NetFox; 6*]Kow?
$?'z%a{
^ S%4R'
public class Utility { p?dMa_g
v#nFPB=z
[u-~<80
public Utility() "5>p]u>
{ v3hNvcMpf
*1>XlVx,
a?D\H5TF-
} 5g/WQo\
D6v0n6w
//线程睡眠 57HMWlg
public static void sleep(int nSecond) "b} ^xy
{ AWf zMJ;VS
try{ SmtH2%yI
Thread.sleep(nSecond); q Rtgk
} .[CXW2k
catch(Exception e) qdcCX:Z<
{ d/* [t!
e.printStackTrace (); w0 "h,{
} m&; t;&#
} >~ne(n4qy
j)J4[j
//日志 (]iw#m{
public static void log(String sMsg) h~F uuL
{ l "d&Sgnj
System.err.println(sMsg); VF6@;5p
} pX!S*(Q{
;jnnCXp>
g3Ff<P P
public static void log(int sMsg) /n:s9eq
{ > m5j.GP;
System.err.println(sMsg); /#Ew{RvW'
} !7}5"j ;A
} Oys.8%+ P
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Que)kjp
/* SYl:X
**TestMethod.java v 7Pv&|
*/ ,Cx5( ~kU
package NetFox; -/FCd(
. vYGJ8(P
8n2*z
public class TestMethod { LkNfcBa_
Mu{mj4Y{
jMd's|#OP
public TestMethod() k*^.-v
{ ///xx/weblogic60b2_win.exe ;r`[6[AG
try{ 9hLPo
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;qzCoe
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '6K WobXm
SiteFileFetch fileFetch = new SiteFileFetch(bean); na/t=<{
fileFetch.start(); -h.']^I
} La3f{;|u5M
catch(Exception e){e.printStackTrace ();} 0w(<pNA
~LkReQI
r^Gl~sX
} lW7kBCsz#
@.MM-
/i$&89yod
public static void main(String[] args) NO6.qWl
{ )u[2TI1
new TestMethod(); abI[J]T9G
} GJ?rqmbL
} Pyk~V)~M
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