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)); SI l<\
} _@]@&^K$E
for(int i=0;i<nEndPos.length-1;i++) :e4[isI
{ g5~1uU$O
nEndPos = nStartPos[i+1]; j98>Jr\
} J@9E20$
nEndPos[nEndPos.length-1] = nFileLength; <Y#EiC.
} /I#SP/M&l
} / ='/R7~
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[~rBnzb
//启动子线程 j0K}nS\ P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; '"Dgov$q
for(int i=0;i<nStartPos.length;i++) dLu3C-.(
{ P-lE,X
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $66DyK?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A|GheH!t
nStartPos,nEndPos,i); O7Awti-X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }qdGS<{
fileSplitterFetch.start(); kKSn^qL*
} $Xo_C_:B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \CE8S+Z%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `ZAGseDd~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Y'i_EX|
nEndPos = " + nFileLength); BBm;QOBU
// fileSplitterFetch[nPos.length-1].start(); r \]iw v
wkZ}o,{*:
6t6#<ts
//等待子线程结束 !Zf)N_k
//int count = 0; ,ffH:3F
//是否结束while循环 -Z%B9ql'
boolean breakWhile = false; 9/S-=VOe.t
4#@zn 2l
s@bo df&
while(!bStop) A&QO]8
{ (}n,Ou[
write_nPos(); jJCd2O]
Utility.sleep(500); A ptzBs/
breakWhile = true; e?~6HP^%.
T#sKld
<P1sK/IZb
for(int i=0;i<nStartPos.length;i++) i;B)@op.#
{ +-OqO3R
if(!fileSplitterFetch.bDownOver) .B9rG~
{ wrW768WR
breakWhile = false; b]U%|bp
break; 9ozUg,+Z|J
} Z:}d\~`x$%
} "#mr?h_
if(breakWhile) j_*#"}Lcp
break; e|ngnkf(G
x5}Ru0Z
m48m5>
//count++; 6muZE1sn
//if(count>4) ,.<l^sj5
// siteStop(); ;M"JN:J8
} 8wqHr@}p
sP5\R#
M7;P)da
System.err.println("文件下载结束！"); f=Rx8I
} jDO[u!J6.%
catch(Exception e){e.printStackTrace ();} *L.+w-g&&
} `8%2F}x}qD
;u0MY
AA$-Lx(UJk
//获得文件长度 dRXF5Ox5K}
public long getFileSize() 1x#Z}XG
{ hqVFb.6[
int nFileLength = -1; H`;q@
try{ Fh4kd>1D
URL url = new URL(siteInfoBean.getSSiteURL()); a$SGFA}V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 14p <0BG
httpConnection.setRequestProperty("User-Agent","NetFox"); fWywegh
0x\bDWZ_
gUB%6vG\I
int responseCode=httpConnection.getResponseCode(); -&* 4~
if(responseCode>=400) SablF2doa
{ q8{)27f,
processErrorCode(responseCode); C-abc+/
return -2; //-2 represent access is error ;X ]+r$_
} dk9'C
}Q?,O
"-+5`!Y
String sHeader; hYMo5?
!giL~}j(R
O!(M:.
for(int i=1;;i++) Ph'P<h:V
{ kw>W5tNpf:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~4\J}Kn
//Utility.log(in.readLine()); |T}Q~
sHeader=httpConnection.getHeaderFieldKey(i); .>0j<|~
if(sHeader!=null) ,=tPh4>
{ `)5E_E3
if(sHeader.equals("Content-Length")) 0m^(|=N-
{ ) )q4Rh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); MV<2x7S
break; 1>1&NQ#}
} Gvk)H$ni
} QQUYWC
else V(|@6ww
break; ^-9g_5
} lU0'5!3R,
} w NlC2is
catch(IOException e){e.printStackTrace ();} mjDaus59
catch(Exception e){e.printStackTrace ();} tk@ T-;
0wCJNXm
-rSpgk0wL
Utility.log(nFileLength); tO$/|B74Bz
h|tdK;)
) N*,cTE
return nFileLength; 0L_JP9e
} N|OI~boV%
$ \j/s:Y
G'oMZb ({=
//保存下载信息（文件指针位置） \YE(E04w57
private void write_nPos() B 3Y,|*
{ K]{Y >w
try{ yF-EHNNf
output = new DataOutputStream(new FileOutputStream(tmpFile)); [%M=nJ{8
output.writeInt(nStartPos.length); Wm{Lg0Nr
for(int i=0;i<nStartPos.length;i++) :nZVP_d+
{ ?8AchbK;N
// output.writeLong(nPos); @7Oqp-
output.writeLong(fileSplitterFetch.nStartPos); )aov]Ns
output.writeLong(fileSplitterFetch.nEndPos); FA}dKE=c Q
} |kPjjVGF{
output.close(); '%.:97
} b!C\J
catch(IOException e){e.printStackTrace ();} K!c "g,S
catch(Exception e){e.printStackTrace ();} rz%8Vigb
} >YwvM=b"V
ztcV[{[g
p.1@4kgK&r
//读取保存的下载信息（文件指针位置） 6ge,2[PU
private void read_nPos() \&K{v#g~
{ B|9)4f&\=R
try{ uIOnP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); nKI]f`P7
int nCount = input.readInt(); +{(f@,&~{
nStartPos = new long[nCount]; (7l'e=J0
nEndPos = new long[nCount]; ,%>]
for(int i=0;i<nStartPos.length;i++) @N,(82k
{ ?RyeZKf
nStartPos = input.readLong(); &M p??{g
nEndPos = input.readLong(); v]UT1d=_T
} |sP;`h}I%
input.close(); 'aYUF&GG
} _Mi`]VSq9
catch(IOException e){e.printStackTrace ();} ]}t6V]`Q
catch(Exception e){e.printStackTrace ();} J:<mq5[
} .E H&GX
v?Z30?_&h
N8hiv'3
private void processErrorCode(int nErrorCode) pZo:\n5o
{ |]--sUx:
System.err.println("Error Code : " + nErrorCode); BG>fLp
} zl?Gd4
hk6(y?#
!&'GWQY{(
//停止文件下载 :w|ef;
public void siteStop() [Dr'
{ GtR!a
bStop = true; !=(OvX_<
for(int i=0;i<nStartPos.length;i++) &PQhJ#YG
fileSplitterFetch.splitterStop(); S$~T8_m^U
#0HZ"n
ST#9auw
} MI^@p`s
} tB S+?N
//负责部分文件的抓取 L|B/'
**FileSplitterFetch.java Q=YIAGK
*/ =geopktpf
package NetFox; H(L.k;B
?4k/V6n@y
kYbqb?
import java.io.*; ~quof>
import java.net.*; 6T"4<w[
``X1xiB
RT+pB{Y
public class FileSplitterFetch extends Thread { R;mA2:W)x
W|X=R?*ZK
b|SDg%e
String sURL; //File URL Q]/ZVcoqo
long nStartPos; //File Snippet Start Position sfD@lW3
long nEndPos; //File Snippet End Position SvTd#>ke
int nThreadID; //Thread's ID #mT\B[4h
boolean bDownOver = false; //Downing is over .r ,wc*SF
boolean bStop = false; //Stop identical Pz\4#E]
FileAccessI fileAccessI = null; //File Access interface |ry![\
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(,nQ7,2EX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k4N_Pa$}\
{ ` nd/N#
this.sURL = sURL; 77 g<`}{
this.nStartPos = nStart; [3K& cX}B
this.nEndPos = nEnd; d-X6yRjnj
nThreadID = id; 8dPDs#Zl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M Ewa^
} |Y-{)5/5}
>W?i+,g
g=#Cc( q
public void run() 4{PN9i E
{ ()'yY^
while(nStartPos < nEndPos && !bStop) .1{:Q1"S
{ NL^;C3u
kAV4V;ydh
53X i)
try{ #%9t-
URL url = new URL(sURL); 9%#u,I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SEKR`2Zz,
httpConnection.setRequestProperty("User-Agent","NetFox"); LZ=E
String sProperty = "bytes="+nStartPos+"-"; NqlU?
httpConnection.setRequestProperty("RANGE",sProperty); /Fr*k5I
Utility.log(sProperty); Z=+Tw!wR>
@23?II$=@
I K9plsd*
InputStream input = httpConnection.getInputStream(); ,=a+;D]'
//logResponseHead(httpConnection); ]F{F+r
$)YalZ
"xI70c{
byte[] b = new byte[1024]; QLm#7ms*y
int nRead; t6q7w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dDg[ry
{ (Sv=R(_s
nStartPos += fileAccessI.write(b,0,nRead); ;W 3#q:
//if(nThreadID == 1) H\%^n<]#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c9ye[81
} ge#0Q L0K
5)c B\N1u
"F[e~S#V*
Utility.log("Thread " + nThreadID + " is over!"); #x+7-hi
bDownOver = true; >b7Yk)[%
//nPos = fileAccessI.write (b,0,nRead); gB<1;_KW
} m2a[E0
catch(Exception e){e.printStackTrace ();} ZGw6Bd_I
} %!\iII
} +@^FUt=tq
{^@vCBE+
(.J6>"K<
//打印回应的头信息 M!`&Z9N
public void logResponseHead(HttpURLConnection con) 7VIfRN{5n
{ &q7}HO/ @
for(int i=1;;i++) Mdw"^x$7
{ {i<L<Y(3
String header=con.getHeaderFieldKey(i); ,Mr_F^|
if(header!=null) .: Zw6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2RU/oqmR
Utility.log(header+" : "+con.getHeaderField(header)); ~v@.YJoZ4Z
else wzj:PS
break; HIqe~Vc
} FrsXLUY
} &c^tJ-s
\zJb}NbnT
%$<v:eMAs
public void splitterStop() XI'.L ~
{ tXCgRU
bStop = true; HGao}@'
} /[qLf:rGI
{,=U]^A
2Rqpok4
} Ofc u4pi
$ba*=/{[q
782 oXyD
/* |;(>q
**FileAccess.java gXj3=N(l
*//文件访问(定位，写) jL{k!V`s
package NetFox; 84lT# ^q
import java.io.*; &s{d r
U6F7dT
d"=)=hm!
public class FileAccessI implements Serializable{ )GfL?'Z
sB*!Nf^y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v'Pbx
RandomAccessFile oSavedFile; Nh01NY;
long nPos; rMoz+{1A
58t_j54
,`8:@<e
public FileAccessI() throws IOException E#E&z(G2
{ ^U6VJ(58P
this("",0); A6I^`0/
} @8Cja.H
<M,<|Y*)
'Yaq; mDY
public FileAccessI(String sName,long nPos) throws IOException V$_.&S?(Y
{ X"V)oC
oSavedFile = new RandomAccessFile(sName,"rw"); k]9y+WC2
this.nPos = nPos; \bies1TBB^
oSavedFile.seek(nPos); QuBA'4ht
} Jim5Ul
\('WS[$2
?^ R"a##
public synchronized int write(byte[] b,int nStart,int nLen) /&E]qc*-p
{ Uuktq)NU
int n = -1; I%jlM0ZUI"
try{ pQxv_4
oSavedFile.write(b,nStart,nLen); Ml,in49
n = nLen; iX6*OEl/Q
} Ri3*au/Q
catch(IOException e) h^YUu`P
{ yJ>Bc
e.printStackTrace (); Z-L}"~
} ~ %Ij5PD
Z6nQW53-
FP")$ ,=s
return n; Q?bC'147O
} hG}gKs
~i]4~bkH2
sw50lId
} YlXqj\a
`[h&Q0Du6
{Q)sR*d
/* W!|l_/L'
**SiteInfoBean.java sT,*<^
*/ L=5Y^f'aU
package NetFox; a{Y8hR
)Wk&c8|y
?weuq"*a
public class SiteInfoBean { }%c0EY'
&w{z
"$3~):o
private String sSiteURL; //Site's URL -,ojZFyRi
private String sFilePath; //Saved File's Path {rzQ[_)EC
private String sFileName; //Saved File's Name x=N0H
private int nSplitter; //Count of Splited Downloading File TpYdIt9#>
T#KVN{O
~ymSsoD^
public SiteInfoBean() J&L#^f*d
{//nSplitter的缺省值为5 As??_=>4
//default value of nSplitter is 5 `69xR[f
this("","","",5); u~!Pzz3"
} \Hu?K\SWs
bV:MOj^
}vZTiuzC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KDr)'gl&
{ V$ho9gQ!l[
sSiteURL= sURL; !,~C
sFilePath = sPath; Gw#z:gX2
sFileName = sName; {5SJ0'.B2g
this.nSplitter = nSpiltter; R8|FqBs
Yez
aW#^@||B
} ]sqp^tQ`e
LAGg(:3f3
-3SRGr
public String getSSiteURL() C9j5Pd5q1L
{ "uBr]N:
return sSiteURL; 6Z-[-0o+g
} ~2UmX'
}7i}dyQv}
k~]\kv=
public void setSSiteURL(String value) w69G6G(
{ sh%%U
sSiteURL = value; 0C717
} rUmnv%qTS
^ lG^.
ze`qf%
public String getSFilePath() 0Hr)h{!F"
{ Oe0dC9H
return sFilePath; (Li)@Cn%
} UO'X"`
zTze%
<7oZV^nd *
public void setSFilePath(String value) 8u Z4[
{ C7!=LiK}
sFilePath = value; ;_1>nXh
} o2^?D`Jr
?e23[
h}%yG{'/M=
public String getSFileName() ; zfBe%Uf
{ aIE\B4w
return sFileName; ScC!?rTW~7
} {\kDu#18Ld
xKoNo^FF
{6*{P!H
public void setSFileName(String value) Of{'A
{ w&}UgtEm
sFileName = value; kN*\yH|
} mh~n#bah
ntF#x.1Pm
0.!Q4bhD
public int getNSplitter() 5O"wPsl
{ uzLIllVX*
return nSplitter; 7 P]Sc
} +e)RT<
dYhLk2
mWU*}-M
public void setNSplitter(int nCount) 0Y\7A
{ |)Sx"B)
nSplitter = nCount; tA9(N>[*
} 1;9 %L@
} CYC6:g|)
4JjO.H
qzu%Pp6If
/* }u'O<d~z?
**Utility.java Uf-`g>
*/ DYCXzFAa
package NetFox; 1H,hw
3yIC@>&y(8
,6a }l;lv
public class Utility { d*<goBd
U_e e3KKA
+yu^Z*_
public Utility() |y7#D9m
{ %LZf=`:(
d:=:l?
2BIOA#@t
} x20sB
>5-]Ur~
//线程睡眠 V %Rz(a+c
public static void sleep(int nSecond) pi?U|&.1z
{ -\=kd {*B
try{ Gnmxp%&}P|
Thread.sleep(nSecond); Yim`3>#t
} eVy\)dCsU
catch(Exception e) ?HaUT(\j
{ Ic&Jhw;]z
e.printStackTrace (); B\Y!5$
} a0x/?)DO
} *G0r4Ui$
-* ;`~5
//日志 #$9rH 2zd
public static void log(String sMsg) o*WI*Fb'
{ @uI_4a
System.err.println(sMsg); v:$Y |mh
} jP|(y]!
\muC_9ke
:j0r~*z-
public static void log(int sMsg) (s.S n(E
{ ur2`.dY>3"
System.err.println(sMsg); !ZlNPPrq}
} &za~=+
} ssC5YtF7X
tmI2BBv
ocT.2/~d
/* l~Sn`%PgA
**TestMethod.java sGD b<
*/ Qf]ACN
package NetFox; SpUcrK;1
JMq00_
Px))O&w{
public class TestMethod { A">A@`}
-!]dU`:(X
nY<hfqof
public TestMethod() D;al(q
{ ///xx/weblogic60b2_win.exe vMOit,{
try{ 1JoRP~mMxa
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #5x[Z[m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )v67wn*1A
SiteFileFetch fileFetch = new SiteFileFetch(bean); H A(e
fileFetch.start(); Lqv5"r7eV
} ]n:)W.|`R
catch(Exception e){e.printStackTrace ();} r:Xui-
1(**JTe
i XI:yE;
} $dLPvN
If_S_A c
JOIbxU{U_
public static void main(String[] args) &~7b-foCq
{ A@0%7xm
new TestMethod(); h4^ a#%$
} zk@KuBLL
} ]l'W=_XDg
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