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)); fhRu-
} (E 8jkc
for(int i=0;i<nEndPos.length-1;i++) Q%!xw(
{ 7<(U`9W/q
nEndPos = nStartPos[i+1]; hH-!3S2'
} H8B.c%_|U
nEndPos[nEndPos.length-1] = nFileLength; p[%~d$JUq
} dD'KP4Io@
} @"98u$5
C~K/yLCAi
p`Tl)[*
//启动子线程 Y#-c<o}f
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; BT;1"l<
for(int i=0;i<nStartPos.length;i++) '43Uv
{ <nV3`L&]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mr_NArF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "Wk K1u
nStartPos,nEndPos,i); 4AvIU!0w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z\QNn
fileSplitterFetch.start(); 3m21n7F4*
} /:BC<]s
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;0$qT$,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )' ,dP)b
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *!Gb_!98
nEndPos = " + nFileLength); CI \O)iB
// fileSplitterFetch[nPos.length-1].start(); [xGL0Z%)t
<; Td8O89_
tBwPB#:W
//等待子线程结束 kDE:KV<"c
//int count = 0; p&`I#6{
//是否结束while循环 2JeEmG9
boolean breakWhile = false; A]o3MoSt
yTe25l{QaF
YY7dw:>e/
while(!bStop) i1b3>H*3
{ KM^}d$x}s
write_nPos(); U}=H1f,
Utility.sleep(500); sv "GX<+
breakWhile = true; (f#{<^gd
RJN LcIm
(V/!0Lj
for(int i=0;i<nStartPos.length;i++) eB,@oo%
{ Tn38]UL
if(!fileSplitterFetch.bDownOver) %F;uW[4r
{ SokU9n!
breakWhile = false; 3rX8H`R
break; `@:k*d
} ,S, R6#3G
} V|nJ%G\
if(breakWhile) xFp9H'j{
break; Pb@$RAU63
;D[I/U
vDc&m
//count++; [{ A5BE -
//if(count>4) q'biTn]2
// siteStop(); 1gYvp9Ma
} :ZM=P3QZ
]tbl1=|
}k8&T\V!
System.err.println("文件下载结束！"); _.,"`U; H
} ~%: TE}
catch(Exception e){e.printStackTrace ();} +]VW[$W
} 4%TmW/yd
2qKAO/_O
;b, bHL
//获得文件长度 'w\Gd7E
public long getFileSize() gaL.5_1
{ |qq29dS?
int nFileLength = -1; {UhpN"'"n
try{ 4&`d$K
URL url = new URL(siteInfoBean.getSSiteURL()); {?IUf~<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bGB5]%v,
httpConnection.setRequestProperty("User-Agent","NetFox"); uv7tbI"r
W}\<}dK
]k.YG!$
int responseCode=httpConnection.getResponseCode(); E `%*lGu_
if(responseCode>=400) P$`k* v
{ &=.7-iC|W
processErrorCode(responseCode); m W4tW
return -2; //-2 represent access is error 6~8dMy;w
} k~$}&O
}iB>3|\
Z2k5qs7g
String sHeader; twPD'X!r
TiI3<.a!
l-[5Zl;"
for(int i=1;;i++) @#5?tk0
{ (G{2ec:?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3HX-lg`0
//Utility.log(in.readLine()); hXn@vK6
sHeader=httpConnection.getHeaderFieldKey(i); T@N)BfkB
if(sHeader!=null) Vjr}"K$Y
{ :HN\A4=kc(
if(sHeader.equals("Content-Length")) [8`^_i=#
{ ery{>|k
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #w)D ml
break; xEe3,tb'e
} 3:!5 ]
} 0av2w5>af
else z8w@pT
break; Y2y = P
} BUEV+SZ4
} I%ZSh]On
catch(IOException e){e.printStackTrace ();} M0RVEhX
catch(Exception e){e.printStackTrace ();} IeE6?!,)
}cI _$
A4VVy~sd
Utility.log(nFileLength); zLVk7u{e
:}fIu?hCA
"NO*(<C.R
return nFileLength; eP|hxqM&9
} aw'o=/a8
bRc~e@
C6}`qD
//保存下载信息（文件指针位置） T:EUI]
private void write_nPos() yvKKE
{ s!K9-qZl<
try{ K9euNa
output = new DataOutputStream(new FileOutputStream(tmpFile)); (k5d.E]CK
output.writeInt(nStartPos.length); 3VmF1w 2
for(int i=0;i<nStartPos.length;i++) 1?ST*b
{ SV_b(wP9
// output.writeLong(nPos); )'t&LWS~
output.writeLong(fileSplitterFetch.nStartPos); @?<1~/sfL
output.writeLong(fileSplitterFetch.nEndPos); 7.1FRxS
} ~C;gEE-
output.close(); EcmyY,w
} Y>'t)PK
catch(IOException e){e.printStackTrace ();} iJ~e8l0CA
catch(Exception e){e.printStackTrace ();} Zk 9i}H
} x?-kt.M
.&c!k1kH
@RVj~J.A
//读取保存的下载信息（文件指针位置） UNKXfe(X9
private void read_nPos() CKRnkTTiV
{ F%e5j9X`
try{ P}bwEj
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tp=/f !bv
int nCount = input.readInt(); WEB enGQ
nStartPos = new long[nCount]; Ng<oz*>U
nEndPos = new long[nCount]; H}&4#CQ'!
for(int i=0;i<nStartPos.length;i++) TY*q[AWG
{ &+F}$8,
nStartPos = input.readLong(); \"hP*DJ"
nEndPos = input.readLong(); r#'E;Yx
} eWAgYe2
input.close(); *v9 {f?
} 8AVG pL
catch(IOException e){e.printStackTrace ();} :l?/]K
catch(Exception e){e.printStackTrace ();} 5Lm<3:7Q+
} 3r,^is
@ Yzj
\I`g[nT|
private void processErrorCode(int nErrorCode) e't1.%w
{ !mRDzr7
System.err.println("Error Code : " + nErrorCode); 3k?|-js
} S.A|(?x
!V;glx[
>>HC|
//停止文件下载 cu$i8$?t
public void siteStop() $79-)4;z4
{ *Wz\FixP0
bStop = true; bR;Wf5
for(int i=0;i<nStartPos.length;i++) AwO'%+Bv
fileSplitterFetch.splitterStop(); ,Taq~
?{*/VJl$
b&Go'C{p
} (J/!9NS:
} K_E- Hgg_
//负责部分文件的抓取 7[u$!.4{*
**FileSplitterFetch.java :yC|Q)
*/ WL/9r *jW
package NetFox; YO^iEI.
W0>fu>
Hg;;>
import java.io.*; AIa#t#8${
import java.net.*; OLM}en_L
0] $5jW6]
/N82h`\n
public class FileSplitterFetch extends Thread { 2k3yf_N
meNz0ve
`di/nv)
String sURL; //File URL BY^5z<^.
long nStartPos; //File Snippet Start Position O/2Jz
long nEndPos; //File Snippet End Position p?zh4:\F+
int nThreadID; //Thread's ID C1KO]e>
boolean bDownOver = false; //Downing is over -$m?ShDd
boolean bStop = false; //Stop identical s.G6?1VXlY
FileAccessI fileAccessI = null; //File Access interface jW!)5(B[A
&SE+7HXw
5uufpvah
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !2Q>
{ o|0QstSCl
this.sURL = sURL; 9F"Q2^l'
this.nStartPos = nStart; fKZgAISF
this.nEndPos = nEnd; jIs2R3B
nThreadID = id; y?s8UEC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mjz<,s`D
} '+{dr\nJ
l]o)KM<
PC}m.tE
public void run() #yVMC;J?W
{ &BDdJwE
while(nStartPos < nEndPos && !bStop) 2r|!:^'?W
{ wk"zpI7L
k_<8SG+`
#XlE_XD
try{ `Gp!Y
URL url = new URL(sURL); _C97G&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oPA [vY
httpConnection.setRequestProperty("User-Agent","NetFox"); fCxF3m(O
String sProperty = "bytes="+nStartPos+"-"; !1\jD
httpConnection.setRequestProperty("RANGE",sProperty); T{%'"mm;
Utility.log(sProperty); az2CFd^M
8fwM)DKS
.xp|w^
InputStream input = httpConnection.getInputStream(); Ew kZzVuX
//logResponseHead(httpConnection); t846:Z%[
W=k%aB?p
Ly$s0.!
byte[] b = new byte[1024]; z.7'yJIP#
int nRead; NJglONO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h8MkfHH7{
{ TGJ\f
nStartPos += fileAccessI.write(b,0,nRead); zUhJr$N$
//if(nThreadID == 1) ?~5J!|r#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Xqac$%[3
} MYb^ILz H3
C8 b%r|^#
HKdR?HM1
Utility.log("Thread " + nThreadID + " is over!"); !bHM:!6^
bDownOver = true; a~-^$Fzgy
//nPos = fileAccessI.write (b,0,nRead); S3k>34_%9
} E|A,NPf%I
catch(Exception e){e.printStackTrace ();} T?Dq2UW
} CF`fn6
} tyLR_@i%%
\#A=twp
P00pSRQHD
//打印回应的头信息 K{&b "Ba1
public void logResponseHead(HttpURLConnection con) 42m}c1R
{ /j1p^=ARV
for(int i=1;;i++) CXsi
{ h8yv:}XU*
String header=con.getHeaderFieldKey(i); .ZxH#l _
if(header!=null) 6GD Uo}.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); S0ct;CS
Utility.log(header+" : "+con.getHeaderField(header)); Y{8L ~U:
else %T&#JF+;
break; YTco;5/
} ^<e"OV
} o\luE{H .?
(qP !x 2j
dIo|i,-
public void splitterStop() nAp7X-t
{ 4D/mm(2d$
bStop = true; >)N}V'9
} Lz VvUVk
_5nQe !
A_t<SG5
} O;A/(lPW+
]rh)AE!Y(
lE54RX}e4
/* ?ExfxR!~
**FileAccess.java \\D~Yg\#
*//文件访问(定位，写) A*h)p@3t<
package NetFox; [^gSWU
import java.io.*; '7F`qL\/#(
H\kqmPl&
y^C;?B<
public class FileAccessI implements Serializable{ -BV&u(
r[$Qtj Q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FVsNOU
RandomAccessFile oSavedFile; z^4\?R50yO
long nPos; _W: S>ij(
WPE@yI(
\~
public FileAccessI() throws IOException RU`TzD
{ FFgy=F
this("",0); Jz#ZDZkm
} qi7wr\XNW
|k'I?:'
XEZ6%Q_
public FileAccessI(String sName,long nPos) throws IOException $Mx.8FC +
{ kmW!0hm;e
oSavedFile = new RandomAccessFile(sName,"rw"); lb1(1|#
this.nPos = nPos; \Mlj 7.u]
oSavedFile.seek(nPos); U gB
} e7L;{+XI
yh5KN_W
Y@.> eS
public synchronized int write(byte[] b,int nStart,int nLen) 9GZF39w u
{ d1j v>tu
int n = -1; LM _4.J
try{ &V( LeSI
oSavedFile.write(b,nStart,nLen); wH#k~`M
n = nLen; CSU>nIE0
} $zCUQthL@
catch(IOException e) $)@zlnU
{ HIhoYSwB
e.printStackTrace (); %h%r6EB1F
} Ro:-u7q
S0=BfkHi.
*OF7{^~&
return n; 73xI8
} l}AB):<Z
^:-%tpB#!
Gz*U?R-T
} oS_p/$F,
<R{\pz2w
/gFyow1W
/* 6}ax~wYct
**SiteInfoBean.java uR"]w7=
*/ 0l_-
package NetFox; `bC_J,>_
u gfV'
5o~Z>
public class SiteInfoBean { dbZPt~S'$
K0I-7/L
)kUq2-r
private String sSiteURL; //Site's URL ?qK:P
private String sFilePath; //Saved File's Path `ZefSmb
private String sFileName; //Saved File's Name FpRK^MEkG
private int nSplitter; //Count of Splited Downloading File #3CA
hV8A<VT
Pq4sv`q)S
public SiteInfoBean() SyYa_=En
{//nSplitter的缺省值为5 _ve7Is`/
//default value of nSplitter is 5 \W@?revK
this("","","",5); sox90o 7
} F37,u|
<I|ryPU9{X
jA]xpf6}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v5$zz w
{ -=qmYf
sSiteURL= sURL; fCVSVn"o
sFilePath = sPath; jN {ED_
sFileName = sName; b'{D4/
this.nSplitter = nSpiltter; YT:5J%"
.HtDcGp
2C8M1^0:Z
} $K G?d>wx
zR<jZwo]#
v^E5'M[A
public String getSSiteURL() oL6_Ya
{ 3> fuH'=
return sSiteURL; ja>Tnfu
} [D?E\Nkk
er<~dqZ}]
(Pu*[STTT
public void setSSiteURL(String value) /V*eAn8>
{ tIvtiN6[|l
sSiteURL = value; 7PvuKAv?k
} [wOO)FjT
O>>8%=5Q
yi%B5KF~Al
public String getSFilePath() 7xd}J(l
{ &`%C'KZ
return sFilePath; 7v:;`6Jb
} %Mu dc
{"y6l
4v?S`w:6
public void setSFilePath(String value) !kz\ {
{ k4l72 'P
sFilePath = value; [j/-(?+
} (nzzX?`nY
D6m>>&E['
r:o!w7C:a
public String getSFileName() \4&g5vE
{ oyd{}$71d
return sFileName; m8f_w
} FPMW"~v
fGfv{4R
Av[jFk
public void setSFileName(String value) C^~iz in
{ ':[y]ep(~|
sFileName = value; ](ninSX1w
} :H87x?e[
:=8vy
doa$ ;=wg
public int getNSplitter() j?,$*Fi
{ {%$=^XO
return nSplitter; mU_O64
} 8L@di Y
xphqgOc12,
GQQ!3LwP\O
public void setNSplitter(int nCount) ])JJ`Z8Bk
{ n-Xj>
nSplitter = nCount; ~+g5?y
} 5SjS~9
} M1i|qjb:l
e?7paJ
prWid3}
/* 'SY&-<t(
**Utility.java g$tW9 Q
*/ BCj&z{5"7e
package NetFox; ?b0\[
,)RdXgCs
'K!kJ9oqe
public class Utility { )>/c/B
OwEz(pj@
G1l(
public Utility() GB=q}@&8p
{ e'`oisJU?q
Uwp +w
QJ/SP
} +EB##
bODl q
//线程睡眠 uu:)jxi
public static void sleep(int nSecond) y{N9.H2
{ p%s D>1k
try{ JjmL6(*ui
Thread.sleep(nSecond); ymzm x$o=
} YJy*OS_&
catch(Exception e) HT&0i,`
{ zxh"@j$?
e.printStackTrace (); = `^jz}
} gr;M
} NR*SEbUU*
>g[W@FhT'k
//日志 QJ>>&`{,
public static void log(String sMsg) a:fHTU=\p
{ =6sXZ"_Tw
System.err.println(sMsg); s:ruCS
} J-}NFWR;t
r)t^qhn
)~/U+,
public static void log(int sMsg) b>i=",i\
{ nqBuC
System.err.println(sMsg); /\#5\dHj
} 8syo_sC |
} @K9T )p]
+@Y[i."^J
+6=!ve}
/* I?K0bs+6
**TestMethod.java cGp^;> ]M
*/ 0 OBkd
package NetFox; ~K9U0ypH
kslN_\
;i9CQ0e?
public class TestMethod { a3;.{6el)H
V|AE~R^
1 XG-O
public TestMethod() MjpJAV/84
{ ///xx/weblogic60b2_win.exe Ps7%:|K]
try{ =CoT{LRQ_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'm|m+K83
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z7q2+;L
SiteFileFetch fileFetch = new SiteFileFetch(bean); (5> ibe
fileFetch.start(); sYXS#;|M
} >-P0wowL
catch(Exception e){e.printStackTrace ();} GHy#D]Z
'T[zh#v>S
kgz{m;R
} sD8S2
]lUu%<-;
o(P:f)B
public static void main(String[] args) RY{tX`
{ g1~I*!p
new TestMethod(); hptuTBD
} 9HX+sB M
} "|%9xGX|D
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